Photoactive additives containing siloxane

ABSTRACT

Photoactive additives are disclosed. Such additives are polymers or oligomers that contain UV-active groups (such as ketone groups) and contain polysiloxane blocks as well. When added to a base polymeric resin and used in molding, this structure promotes migration of the additive to the surface. Crosslinking occurs upon exposure to ultraviolet light.

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/789,243, filed Mar. 15, 2013. The disclosure of thatapplication is hereby fully incorporated by reference herein.

BACKGROUND

The present disclosure relates to photoactive additives containing aphotoactive group and polysiloxane blocks. These additives can be usedfor crosslinking polymers. More particularly, it is believed that theseadditives will preferentially migrate to the surface of articles formedtherefrom, enhancing the crosslinking effect. Also included arecompositions including such additives, as well as products (e.g. moldedarticles, sheets, films, etc.) formed from such methods andcompositions.

Polycarbonates (PC) are synthetic engineering thermoplastic resins, andare a useful class of polymers having many beneficial properties.Polycarbonate resins are both strong and transparent, and are used for anumber of different commercial applications, including electronicengineering (E&E) parts, mechanical parts, etc.

Polycarbonate polymers/resins and blends containing polycarbonatepolymers exhibit flame retardance properties. However, such polymersdrip when exposed to a flame, and this behavior worsens as the wallthickness decreases. This behavior greatly diminishes their use intransparent and opaque thin wall applications where a V0 or 5VA flameretardance rating is required. These polymers also have relatively poorchemical resistance. It would be desirable to provide additives that canimprove these properties.

BRIEF DESCRIPTION

The present disclosure is directed to additives that contain photoactivegroups and polysiloxane blocks. The additives are formed by the reactionof at least a first photoactive moiety with a first linker moiety and apolysiloxane monomer. Generally, carbonate or ester linkages are foundin the additives. The additives can be used to crosslink resins andimprove their flame resistance and/or chemical resistance.

Additionally, the present disclosure is directed to processes ofimproving characteristics, such as chemical or flame resistance, of aresin or composition, and/or articles formed therefrom, by promotingmigration of ultraviolet light active oligomers/polymers to the surface.For example, in one non-limiting embodiment, the disclosure relates to amethod of promoting migration of a photoactive additive to the surfaceof a molded article by incorporating a polysiloxane monomer in thephotoactive additive. The molded article is then subsequentlycross-linked with light of a certain wavelength, such as ultravioletlight, producing an article with enhanced characteristics.

Disclosed in several embodiments herein are photoactive additives thatare a cross-linkable polycarbonate terpolymer formed from a reactioncomprising: a dihydroxybenzophenone; a first linker moiety comprising aplurality of functional groups, wherein each functional group reactswith the hydroxyl groups of the dihydroxybenzophenone; a diol chainextender; an end-capping agent; and a polysiloxane monomer in an amountsuch that the additive contains from 1 wt % to 25 wt % of siloxane,based on the total weight of the polycarbonate terpolymer.

In particular specific embodiments, the dihydroxybenzophenone is4,4′-dihydroxybenzophenone; the diol chain extender is bisphenol-A; andthe first linker moiety is phosgene.

The additive may contain from about 0.5 mole % to about 50 mole % of thedihydroxybenzophenone. Alternatively, the additive may contain fromabout 1 wt % to about 25 wt % of the dihydroxybenzophenone.

The end-capping agent can be selected from the group consisting ofphenol, p-t-butylphenol, p-cumylphenol, octylphenol, p-cyanophenol, anda monohydroxybenzophenone.

The polysiloxane monomer may have the structure of one of Formulas(I)-(III), as defined further herein. The diol chain extender may havethe structure of one of Formulas (A)-(G), as defined further herein. Thefirst linker moiety may have the structure of one of Formulas (30),(32), or (33), as defined further herein.

The additive of claim 1, wherein the molar ratio of thedihydroxybenzophenone to the first linker moiety may be from 1:2 to1:200.

The reaction that forms the photoactive additive can further comprise asecondary linker moiety having at least three functional groups, each ofwhich can react with a functional group of the first linker moiety. Thesecondary linker moiety can have the structure of one of Formulas(43)-(48), as defined further herein.

The additive can have a weight average molecular weight of 15,000 orgreater. In particular embodiments, the cross-linkable polycarbonateterpolymer has a weight-average molecular weight from 17,000 to 80,000Daltons, as measured by gel permeation chromatography using a UV-VISdetector and polycarbonate standards.

In many embodiments, a molded part formed from the cross-linkablepolycarbonate terpolymer exhibits 100% ductility at minus 20° C. at 3.2mm thickness in a notched Izod test according to ASTM D256.

Also disclosed are products formed from a composition comprising thephotoactive additive of claim 1. The product can be a molded article, afilm, a sheet, a layer of a multilayer film, or a layer of a multilayersheet. The product may be formed by injection molding, overmolding,co-injection molding, extrusion, multilayer extrusion, rotationalmolding, blow molding, or thermoforming. In particular embodiments, theproduct is exposed to UV radiation to cause crosslinking of thephotoactive additive.

Also disclosed are blends comprising the additive of claim 1 and apolymeric base resin that is different from the photoactive additive.

Also disclosed are processes for making a photoactive additive from adihydroxybenzophenone, a diol chain extender, a polysiloxane monomer, anend-capping agent, a carbonate precursor, a base, a tertiary aminecatalyst, water, and a water-immiscible organic solvent, comprising:pre-reacting the polysiloxane monomer with the carbonate precursor in atubular reactor to form chloroformates; combining thedihydroxybenzophenone, diol chain extender, tertiary amine catalyst,water, and water-immiscible solvent to form a reaction mixture; addingthe carbonate precursor to the reaction mixture over a first time periodwhile co-adding the base to regulate the reaction pH; adding theend-capping agent and the chloroformates to the reaction mixture for asecond time period while continuing to add the carbonate precursor andthe base; and continuing to add the carbonate precursor and the base tothe reaction mixture for a third time period after the second timeperiod is complete to obtain the photoactive additive; wherein thepolysiloxane monomer is present in an amount such that the additivecontains from 1 wt % to 25 wt % of siloxane, based on the total weightof the polycarbonate resin.

In particular embodiments, the carbonate precursor is phosgene, the diolchain extender is bisphenol-A, the base is an alkali metal hydroxide,and the water-immiscible organic solvent is methylene chloride.

The end-capping agent can be dissolved in a solvent prior to being addedto the reaction mixture, the solvent being either the water-immiscibleorganic solvent or water containing a base. More specifically, theend-capping agent cane be dissolved in a dilute aqueous sodium hydroxidesolution. In specific embodiments, the solution contains from about 1 toabout 2 moles of NaOH per mole of the end-capping agent, and containsfrom about 5 wt % to about 20 wt % of the end-capping agent compound.

The reaction pH is generally regulated to remain between about 8.5 andabout 10.

Also disclosed herein is a cross-linkable polycarbonate terpolymerformed from a reaction comprising a dihydroxybenzophenone, a diol chainextender, and a polysiloxane monomer in an amount such that theterpolymer contains from 1 wt % to 25 wt % of siloxane, based on thetotal weight of the terpolymer, wherein the terpolymer is formed by:pre-reacting the polysiloxane monomer with a carbonate precursor in atubular reactor to form chloroformates; combining thedihydroxybenzophenone, the diol chain extender, a tertiary aminecatalyst, water, and a water-immiscible solvent to form a reactionmixture; adding the carbonate precursor to the reaction mixture over afirst time period while co-adding the base to regulate the reaction pH;adding the chloroformates to the reaction mixture for a second timeperiod while continuing to add the carbonate precursor and the base;continuing to add the carbonate precursor and the base to the reactionmixture for a third time period after the second time period is completeto obtain the terpolymer.

Additionally disclosed herein are crosslinked layers formed from apolymeric blend that has been exposed to UV radiation, the blendcomprising: (a) a photoactive additive that is a cross-linkablepolycarbonate terpolymer formed from a reaction comprising adihydroxybenzophenone, a diol chain extender, and a polysiloxane monomerin an amount such that the terpolymer contains from 1 wt % to 25 wt % ofsiloxane, based on the total weight of the terpolymer; and (b) a polymerresin which is different from the photoactive additive. The crosslinkedlayer usually contains chains from both the photoactive additive and thepolymer resin. The crosslinking can be sufficient to create a continuousinsoluble layer containing both the photoactive additive and the polymerresin.

These and other non-limiting characteristics are more particularlydescribed below.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief description of the drawings, which arepresented for the purposes of illustrating the exemplary embodimentsdisclosed herein and not for the purposes of limiting the same.

FIG. 1 illustrates the formation of a photoactive additive(oligomer/polymer) from a difunctional photoactive moiety, a firstlinker moiety, a chain extender, an end-capping agent, and apolysiloxane monomer.

FIG. 2 illustrates the formation of a photoactive additive(oligomer/polymer) from a monofunctional photoactive moiety that acts asan endcap, a polysiloxane monomer, a diol chain extender, and a firstlinker moiety.

FIG. 3 illustrates the crosslinking mechanism of the photoactiveadditive.

DETAILED DESCRIPTION

The present disclosure may be understood more readily by reference tothe following detailed description of desired embodiments and theexamples included therein. In the following specification and the claimswhich follow, reference will be made to a number of terms which shall bedefined to have the following meanings.

DEFINITIONS

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art. In case of conflict, the present document, includingdefinitions, will control. Preferred methods and materials are describedbelow, although methods and materials similar or equivalent to thosedescribed herein can be used in practice or testing of the presentinvention. All publications, patent applications, patents and otherreferences mentioned herein are incorporated by reference in theirentirety. The materials, methods, and examples disclosed herein areillustrative only and not intended to be limiting.

The singular forms “a,” “an,” and “the” include plural referents unlessthe context clearly dictates otherwise.

As used in the specification and in the claims, the term “comprising”may include the embodiments “consisting of” and “consisting essentiallyof.” The terms “comprise(s),” “include(s),” “having,” “has,” “can,”“contain(s),” and variants thereof, as used herein, are intended to beopen-ended transitional phrases, terms, or words that require thepresence of the named ingredients/steps and permit the presence of otheringredients/steps. However, such description should be construed as alsodescribing compositions or processes as “consisting of” and “consistingessentially of” the enumerated ingredients/steps, which allows thepresence of only the named ingredients/steps, along with any impuritiesthat might result therefrom, and excludes other ingredients/steps.

Numerical values in the specification and claims of this application,particularly as they relate to polymers or polymer compositions, reflectaverage values for a composition that may contain individual polymers ofdifferent characteristics. Furthermore, unless indicated to thecontrary, the numerical values should be understood to include numericalvalues which are the same when reduced to the same number of significantfigures and numerical values which differ from the stated value by lessthan the experimental error of conventional measurement technique of thetype described in the present application to determine the value.

All ranges disclosed herein are inclusive of the recited endpoint andindependently combinable (for example, the range of “from 2 grams to 10grams” is inclusive of the endpoints, 2 grams and 10 grams, and all theintermediate values). The endpoints of the ranges and any valuesdisclosed herein are not limited to the precise range or value; they aresufficiently imprecise to include values approximating these rangesand/or values.

As used herein, approximating language may be applied to modify anyquantitative representation that may vary without resulting in a changein the basic function to which it is related. Accordingly, a valuemodified by a term or terms, such as “about” and “substantially,” maynot be limited to the precise value specified, in some cases. In atleast some instances, the approximating language may correspond to theprecision of an instrument for measuring the value. The modifier “about”should also be considered as disclosing the range defined by theabsolute values of the two endpoints. For example, the expression “fromabout 2 to about 4” also discloses the range “from 2 to 4.” The term“about” may refer to plus or minus 10% of the indicated number. Forexample, “about 10%” may indicate a range of 9% to 11%, and “about 1”may mean from 0.9-1.1. Other meanings of “about” may be apparent fromthe context, such as rounding off, so, for example “about 1” may alsomean from 0.5 to 1.4.

For the recitation of numeric ranges herein, each intervening numberthere between with the same degree of precision is explicitlycontemplated. For example, for the range of 6-9, the numbers 7 and 8 arecontemplated in addition to 6 and 9, and for the range 6.0-7.0, thenumber 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 areexplicitly contemplated.

Compounds are described using standard nomenclature. For example, anyposition not substituted by any indicated group is understood to haveits valency filled by a bond as indicated, or a hydrogen atom. A dash(“-”) that is not between two letters or symbols is used to indicate apoint of attachment for a substituent. For example, the aldehyde group—CHO is attached through the carbon of the carbonyl group.

The term “aliphatic” refers to a linear or branched array of atoms thatis not aromatic. The backbone of an aliphatic group is composedexclusively of carbon. The aliphatic group may be substituted orunsubstituted. Exemplary aliphatic groups include, but are not limitedto, methyl, ethyl, isopropyl, hexyl, and cyclohexyl.

The term “aromatic” refers to a radical having a ring system containinga delocalized conjugated pi system with a number of pi-electrons thatobeys Hückel's Rule. The ring system may include heteroatoms such asnitrogen, sulfur, selenium, silicon and oxygen, or may be composedexclusively of carbon and hydrogen. Aromatic groups are not substituted.Exemplary aromatic groups include, but are not limited to, phenyl,pyridyl, furanyl, thienyl, naphthyl and biphenyl.

The term “ester” refers to a radical of the formula —CO—O—, wherein thecarbon atom and the oxygen atom are both covalently bonded to carbonatoms.

The term “carbonate” refers to a radical of the formula —O—CO—O—,wherein the oxygen atoms are both covalently bonded to carbon atoms.Note that a carbonate group is not an ester group, and an ester group isnot a carbonate group.

The term “hydroxyl” refers to a radical of the formula —OH, wherein theoxygen atom is covalently bonded to a carbon atom.

The terms “carboxy” or “carboxyl” refer to a radical of the formula—COOH, wherein the carbon atom is covalently bonded to another carbonatom. It should be noted that for the purposes of this disclosure, acarboxyl group may be considered as having a hydroxyl group. However, itshould be noted that a carboxyl group can participate in certainreactions differently from a hydroxyl group.

The term “alkyl” refers to a radical composed entirely of carbon atomsand hydrogen atoms which is fully saturated. The alkyl radical may belinear, branched, or cyclic.

The term “aryl” refers to an aromatic radical that is composedexclusively of carbon and hydrogen. Exemplary aryl groups includephenyl, naphthyl, and biphenyl. Note that “aryl” is a subset ofaromatic.

The term “heteroaryl” refers to an aromatic radical having a ring systemthat is composed of carbon, hydrogen, and at least one heteroatom.Exemplary heteroaryl groups include pyridyl, furanyl, and thienyl. Notethat “heteroaryl” is a subset of aromatic, and is exclusive of “aryl”.

The term “halogen” refers to fluorine, chlorine, bromine, and iodine.

The term “alkoxy” refers to an alkyl radical which is attached to anoxygen atom, i.e. —O—C_(n)H_(2n+1).

The term “aryloxy” refers to an aryl radical which is attached to anoxygen atom, e.g. —O—C₆H₅.

The term “hydrocarbon” refers to a radical which is composed exclusivelyof carbon and hydrogen. Both alkyl and aryl groups are consideredhydrocarbon groups.

The term “alkenyl” refers to a radical composed entirely of carbon atomsand hydrogen atoms which contains at least one carbon-carbon double bondthat is not part of an aryl or heteroaryl structure. The alkenyl radicalmay be linear, branched, or cyclic. An exemplary alkenyl radical isvinyl (—CH═CH₂).

The term “alkenyloxy” refers to an alkenyl radical which is attached toan oxygen atom, e.g. —O—CH═CH₂.

The term “arylalkyl” refers to an aryl radical which is attached to analkyl radical, e.g. benzyl (—CH₂—C₆H₅).

The term “alkylaryl” refers to an alkyl radical which is attached to anaryl radical, e.g. tolyl (—C₆H₄—CH₃).

The term “nitro” refers to a radical of the formula —NO₂.

The term “cyano” refers to a radical of the formula —C≡N.

The term “copolymer” refers to a polymer derived from two or morestructural unit or monomeric species, as opposed to a homopolymer, whichis derived from only one structural unit or monomer.

The terms “Glass Transition Temperature” or “Tg” refer to the maximumtemperature that a polymer, such as a polycarbonate, will have one ormore useful properties. These properties include impact resistance,stiffness, strength, and shape retention. The Tg of a polycarbonatetherefore may be an indicator of its useful upper temperature limit,particularly in plastics applications. The Tg may be measured using adifferential scanning calorimetry method and expressed in degreesCelsius. The glass transition temperatures (Tg) described herein aremeasures of heat resistance of, for example, polycarbonate andpolycarbonate blends. The Tg can be determined by differential scanningcalorimetry, for example by using a TA Instruments Q1000 instrument, forexample, with setting of 20° C./min ramp rate and 40° C. starttemperature and 200° C. end temperature.

The term “halo” means that the substituent to which the prefix isattached is substituted with one or more independently selected halogenradicals. For example, “C₁-C₆ haloalkyl” means a C₁-C₆ alkyl substituentwherein one or more hydrogen atoms are replaced with independentlyselected halogen radicals. Non-limiting examples of C₁-C₆ haloalkylinclude chloromethyl, 1-bromoethyl, fluoromethyl, difluoromethyl,trifluoromethyl, and 1,1,1-trifluoroethyl. It should be recognized thatif a substituent is substituted by more than one halogen radical, thosehalogen radicals may be identical or different (unless otherwisestated).

The term “haze” refers to the percentage of transmitted light, which inpassing through a specimen deviates from the incident beam by forwardscattering. Percent (%) haze may be measured according to ASTM D1003-07.

The term “Melt Volume Rate” (MVR) or “Melt Flow Rate (MFR)” refers tothe flow rate of a polymer in a melt phase as determined using themethod of ASTM D1238-10. The MVR of a molten polymer is measured bydetermining the amount of polymer that flows through a capillary of aspecific temperature over a specified time using standard weights at afixed temperature. MVR is expressed in cubic centimeter per 10 minutes,and MFR is expressed in grams per 10 minutes. The higher the MVR or MFRvalue of a polymer at a specific temperature, the greater the flow ofthat polymer at that specific temperature.

The term “Percent transmission” or “% transmission” refers to the ratioof transmitted light to incident light, and may be measured according toASTM D 1003-07.

“Polycarbonate” as used herein refers to an oligomer or a polymercomprising residues of one or more monomers, joined by carbonatelinkages.

“Thermal stability” as used herein refers to resistance of a polymer tomolecular weight degradation under thermal conditions. Thus, a polymerwith poor thermal stability may show significant molecular weightdegradation under thermal conditions, such as during extrusion, molding,thermoforming, hot-pressing, and like conditions. Molecular weightdegradation may also be manifest through color formation and/or in thedegradation of other properties such as weatherability, gloss,mechanical properties, and/or thermal properties. Molecular weightdegradation can also cause significant variation in processingconditions such as melt viscosity changes.

The term “crosslink” and its variants refer to the formation of a stablecovalent bond between two polymers/oligomers. This term is intended toencompass the formation of covalent bonds that result in networkformation, or the formation of covalent bonds that result in chainextension. The term “cross-linkable” refers to the ability of apolymer/oligomer to form such stable covalent bonds.

The present disclosure refers to “polymers,” “oligomers”, and“compounds”. A polymer is a large molecule composed of multiplerepeating units chained together, the repeating units being derived froma monomer. One characteristic of a polymer is that different moleculesof a polymer will have different lengths, and a polymer is described ashaving a molecular weight that is based on the average value of thechains (e.g. weight average or number average molecular weight). The artalso distinguishes between an “oligomer” and a “polymer”, with anoligomer having only a few repeating units, while a polymer has manyrepeating units. For purposes of this disclosure, the term “oligomer”refers to such molecules having a weight average molecular weight ofless than 15,000, and the term “polymer” refers to molecules having aweight average molecular weight of 15,000 of more, as measured by GPCusing polycarbonate molecular weight standards. In contrast, for acompound, all molecules will have the same molecular weight. Compared toa polymer, a compound is a small molecule. These molecular weights aremeasured prior to any UV exposure.

Additives

The present disclosure relates to photoactive additives (PAA), and tocompositions containing such additives. When the photoactive additive isadded to one or more base resins and is then exposed to the appropriatewavelength of light, the resulting composition will have improvedanti-drip and flame retardant properties compared to the base resinsalone or to the composition prior to the light exposure. For example,the chemical resistance, propensity to drip during burning, or thepropensity to form a hole when exposed to a flame can be improved.Improved flame resistance performance characteristics may include flameout time (FOT) and time to drip (TTD). The compositions, blended orneat, can be used to provide thin-walled materials that are UL94 5VAcompliant. The compositions can be used to provide thin-walled materialsthat are 5VA compliant and highly transparent. The compositions may alsoexhibit good chemical resistance, tear resistance, impact strength,ductility, hydrolytic stability, and/or weatherability.

Generally, the photoactive additives (PAA) of the present disclosureinclude photoactive moieties that are covalently linked together througha first linker moiety and possibly a secondary linker moiety. Thephotoactive moieties contain a ketone group that, when exposed to theappropriate wavelength(s) of ultraviolet light, will form a stablecovalent bond between the PAA and the polymeric resin. The PAA alsocontains polysiloxane blocks to promote migration, as explained furtherherein. The PAA should be stable at conventional blending, forming, andprocessing temperatures (i.e. stable at 350° C. or above). The PAA alsoshould not induce the degradation of the polymeric resin with which itis blended.

The term “photoactive moiety” refers to a moiety that, when exposed toultraviolet light of the appropriate wavelength, crosslinks with anothermolecule. Thus, for example, the bisphenol-A monomer in a bisphenol-Ahomopolymer would not be considered a photoactive moiety, even thoughphoto-Fries rearrangement can occur upon exposure to light, because theatoms do not participate in crosslinking but merely in rearrangement ofthe polymer backbone.

The photoactive additive is formed from a reaction mixture containing atleast a first photoactive moiety, a first linker moiety, and apolysiloxane monomer. The photoactive moiety comprises (i) a ketonegroup and (ii) two hydroxyl groups. The first linker moiety comprises aplurality of functional groups that can react with the hydroxyl group(s)of the photoactive moiety and the polysiloxane monomer. The reactionproduct is the photoactive additive (PAA). The molar ratio of thephotoactive moiety to the first linker moiety can be from 1:2 to 1:200.The molar ratio of the photoactive moiety to the polysiloxane monomercan be from 1:20 to 20:1. An end-capping agent may also be included. Adiol chain extender is usually also included. The end-capping agent andthe diol chain extender do not have photoactive properties.

The term “ketone group” refers to a carbonyl group (—CO—) that is bondedto two other carbon atoms (i.e. —R—CO—R′—). The two other carbon atomscan be in an aliphatic group or in an aromatic group. An ester group anda carboxylic acid group are not considered to be a ketone group becausethe carbonyl group is bonded to one carbon atom and an oxygen atom.

In many embodiments, the hydroxyl group(s) of the photoactive moiety arephenolic groups. The term “phenolic group” refers to a phenyl group(—C₆H₄—) with a hydroxyl group (—OH) covalently bonded to a carbon atomin the phenyl group. In other embodiments, the hydroxyl group(s) of thephotoactive moiety are carboxyl groups.

The photoactive moiety can be a hydroxyphenone, wherein the phenolicgroup is directly bonded to the ketone group. In particular embodiments,the photoactive moiety contains only two phenolic groups. Examples ofsuch photoactive moieties include those having the structure of one ofFormulas (16)-(21):

wherein R is H, alkyl, or aryl.

The compound of Formula (16) is a dihydroxyphenyl-phenylmethanone. Thecompound of Formula (17) is a bis(hydroxyphenyl)methanone. The compoundsof Formulas (16) or (17) could also be referred to asdihydroxybenzophenones. The compound of Formula (18) is a1-dihydroxyphenyl-2-phenylethane-1,2-dione. The compound of Formula (19)is a 1,2-bis(hydroxyphenyl)ethane-1,2-dione. The compounds of Formulas(18) or (19) could also be referred to as dihydroxybenzils. The compoundof Formula (20) is a1-(dihydroxyphenyl)-2-hydrocarboxy-2-phenylethanone. The compound ofFormula (21) is a 1,2-bis(hydroxyphenyl)-2-hydrocarboxy-ethanone.

Again, in some other embodiments, the R and R′ groups attached to theketone group form a ring structure. In such embodiments, the aromaticrings can include both aryl rings or heteroaryl rings. Examples of suchphotoactive moieties include those having the structure of one ofFormulas (22)-(29):

The compounds of Formula (22) and (23) are adihydroxy-9,10-anthraquinone. The compounds of Formula (24) and (23) area dihydroxy-9-fluorenone. The compounds of Formula (26) and (23) are adihydroxydibenzo[1,3-e:1′,2′-f][7]annulen-11-one. The compounds ofFormula (28) and (23) are a dihydroxythioxanthen-9-one. The differentformulas reflect the location of the two hydroxyl groups (either on thesame ring, or on a different ring). In particular embodiments, thephotoactive moiety is 4,4′-dihydroxybenzophenone

The photoactive moiety is reacted with one or more first linkermoieties, and with a polysiloxane monomer. At least one of the firstlinker moieties comprises a plurality of functional groups that canreact with the phenolic group(s) of the photoactive moiety and thepolysiloxane monomer. Examples of such functional groups include acarboxylic acid (and anhydrides thereof), an acyl halide, an alkylester, and an aryl ester. These functional groups are illustrated belowin general formula (A):

where Y is hydroxyl, halogen, alkoxy, or aryloxy. The functional groupscan be joined to an aliphatic group or an aromatic group which serves asa “backbone” for the linker moiety. In particular embodiments, thelinker moiety can have two, three, four, or even more functional groups.

Some examples of first linker moieties which have two functional groupsand can react with the photoactive moieties include those having thestructure of one of Formulas (30, (32), or (33):

where Y is hydroxyl, halogen, alkoxy, or aryloxy; and where n is 1 to20. It should be noted that Formula (33) encompasses isophthalic acidand terephthalic acid.

Some examples of first linker moieties which have three functionalgroups and can react with the photoactive moieties include those havingthe structure of one of Formulas (36)-(38):

where Y is hydroxyl, halogen, alkoxy, or aryloxy.

Some examples of first linker moieties which have four functional groupsand can react with the photoactive moieties include those having thestructure of one of Formulas (39)-(41):

where Y is hydroxyl, halogen, alkoxy, or aryloxy.

In some embodiments, functional groups can be provided by shortoligomers, including oligomers containing glycidyl methacrylate monomerswith styrene or methacrylate monomers, or epoxidized novolac resins.These oligomers can permit the desired the number of functional groupsto be provided. Such oligomers are generalized by the structure ofFormula (42):

where E is hydrogen or an endcapping agent, p is the number ofmethacrylate monomers, q is the number of methacrylate monomers, r isthe number of styrene monomers, and t is the number of epoxidizednovolac (phenol-formaldehyde)monomers. Generally, p+q+r+t 20. When theoligomer contains glycidyl methacrylate monomers with styrene ormethacrylate monomers, generally t=0 and q≧1. Similarly, for novolacresins, p=q=r=0. The epoxy groups can be reacted with the phenolic groupof the photoactive moiety.

A polysiloxane monomer is also reacted with the photoactive moiety andthe first linker moiety. This results in an oligomer/polymer containingpolycarbonate blocks and polysiloxane blocks. One exemplary polysiloxanemonomer has the structure of Formula (I):

wherein each Ar is independently aryl; each R is independently alkyl,alkoxy, alkenyl, alkenyloxy, aryl, aryloxy, arylalkyl, or alkylaryl; andD is an average value of 2 to about 1000, specifically about 2 to about500, more specifically about 10 to about 75. Compounds of this formulamay be obtained by the reaction of a dihydroxyarylene compound with, forexample, an alpha,omega-bisacetoxypolydiorangonosiloxane under phasetransfer conditions.

Another exemplary polysiloxane monomer has the structure of Formula(II):

wherein each R is independently alkyl, alkoxy, alkenyl, alkenyloxy,aryl, aryloxy, arylalkyl, or alkylaryl; and D is an average value of 2to about 1000, specifically about 2 to about 500, more specificallyabout 10 to about 75; each M is independently cyano, nitro, alkyl,alkoxy, alkenyl, alkenyloxy, aryl, aryloxy, arylalkyl, or alkylaryl;each n is independently an integer from 0 to 4; and each R₂ isindependently an aliphatic group. Compounds of this formula may beobtained by the reaction of a siloxane hydride with an aliphaticallyunsaturated monohydric phenol. Suitable aliphatically unsaturatedmonohydric phenols include, for example, eugenol, 2-alkylphenol,4-allyl-2-methylphenol, 4-allyl-2-phenylphenol,4-allyl-2-t-butoxyphenol, 4-phenyl-2-phenylphenol,2-methyl-4-propylphenol, 2-allyl-4,6-dimethylphenol,2-allyl-6-methoxy-4-methylphenol and 2-allyl-4,6-dimethylphenol.Mixtures comprising at least one of the foregoing may also be used.

A third exemplary polysiloxane monomer has the structure of Formula(III):

wherein each R is independently alkyl, alkoxy, alkenyl, alkenyloxy,aryl, aryloxy, arylalkyl, or alkylaryl; each R₆ is independently adivalent C₁-C₃₀ organic group such as a C₁-C₃₀ alkyl, C₁-C₃₀ aryl, orC₁-C₃₀ alkylaryl; and E is an average value of 2 to about 1000,specifically about 2 to about 500, or about 10 to about 200, or morespecifically about 10 to about 75. It is noted that D and E haveidentical values in Formulas (I)-(III).

Specific examples of polysiloxane monomers that can be used hereinFormulas (a) through (d):

where E is an average value from 10 to 200.

If desired, the photoactive additive can be formed from a reactionmixture containing the photoactive moiety, the first linker moiety, thepolysiloxane monomer, and one or more diol chain extenders. The diolchain extender is a molecule that contains only two hydroxyl groups andis not photoactive when exposed to light. The chain extender can be usedto provide a desired level of miscibility when the additive is mixedwith other polymeric resins.

A first exemplary chain extender is a bisphenol of Formula (A):

wherein R^(a) and R^(b) each represent a halogen atom or a monovalenthydrocarbon group and may be the same or different; p and q are eachindependently integers of 0 to 4; and A represents one of the groups offormula (A-1):

wherein R^(c) and R^(d) each independently represent a hydrogen atom ora monovalent linear or cyclic hydrocarbon group and R^(e) is a divalenthydrocarbon group.

Specific examples of the types of bisphenol compounds that may berepresented by Formula (A) include 1,1-bis(4-hydroxyphenyl)methane,1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane(hereinafter “bisphenol-A” or “BPA”), 2,2-bis(4-hydroxyphenyl)butane,2,2-bis(4-hydroxyphenyl)octane, 1,1-bis(4-hydroxyphenyl)propane,1,1-bis(4-hydroxyphenyl)n-butane,2,2-bis(4-hydroxy-1-methylphenyl)propane, and1,1-bis(4-hydroxy-t-butylphenyl)propane;4,4′-(1-phenylethane-1,1-diyl)diphenol or1,1-bis(4-hydroxyphenyl)-1-phenyl-ethane (bisphenol-AP); and1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane) (bisphenol TMC).

A second exemplary chain extender is a bisphenol of Formula (B):

wherein each R^(k) is independently a C₁₋₁₀ hydrocarbon group, and n is0 to 4. The halogen is usually bromine. Examples of compounds that maybe represented by Formula (B) include resorcinol, substituted resorcinolcompounds such as 5-methyl resorcinol, 5-phenyl resorcinol, or 5-cumylresorcinol; catechol; hydroquinone; and substituted hydroquinones suchas 2-methyl hydroquinone, 2-t-butyl hydroquinone, 2-phenyl hydroquinone,2-cumyl hydroquinone, or 2,3,5,6-tetramethyl hydroquinone.

A third exemplary chain extender is an aliphatic diol of Formula (C):

wherein each X is independently hydrogen, halogen, or alkyl; and j is aninteger from 1 to 20. Examples of an aliphatic diol include ethyleneglycol, propanediol, 2,2-dimethyl-propanediol, 1,6-hexanediol, and1,12-dodecanediol.

A fifth exemplary diol chain extender is a dihydroxy compound of Formula(D), which may be useful for high heat applications:

wherein R¹³ and R¹⁵ are each independently a halogen or a C₁-C₆ alkylgroup, R¹⁴ is a C₁-C₆ alkyl, phenyl, or phenyl substituted with up tofive halogens or C₁-C₆ alkyl groups, and c is 0 to 4. In a specificembodiment, R¹⁴ is a C₁-C₆ alkyl or phenyl group. In still anotherembodiment, R¹⁴ is a methyl or phenyl group. In another specificembodiment, each c is 0. Compounds of Formula (D) include3,3-bis(4-hydroxyphenyl)-2-phenylisoindolin-1-one (PPPBP).

Other dihydroxy compounds (i.e. diol chain extenders) that might imparthigh Tgs to the polycarbonate as a copolycarbonate are dihydroxycompounds having adamantane units, as described in U.S. Pat. No.7,112,644 and U.S. Pat. No. 3,516,968, which are fully incorporatedherein by reference. A compound having adamantane units may haverepetitive units of the following formula (E) for high heatapplications:

wherein R₁ represents a halogen atom, an alkyl group having 1 to 6carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl grouphaving 6 to 12 carbon atoms, an aryl-substituted alkenyl group having 7to 13 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms;R₂ represents a halogen atom, an alkyl group having 1 to 12 carbonatoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having6 to 12 carbon atoms, an aryl-substituted alkenyl group having 7 to 13carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms; mrepresents an integer of 0 to 4; and n represents an integer of 0 to 14.

Other dihydroxy compounds that might impart high Tgs to thepolycarbonate as a copolycarbonate are dihydroxy compounds havingfluorene-units, as described in U.S. Pat. No. 7,244,804. One suchfluorene-unit containing dihydroxy compound is represented by thefollowing formula (F) for high heat applications:

wherein R₁ to R₄ are each independently a hydrogen atom, a hydrocarbongroup with 1 to 9 carbon atoms which may contain an aromatic group, or ahalogen atom.

Another diol chain extender that could be used is an isosorbide. Amonomer unit derived from isosorbide may be an isorbide-bisphenol unitof Formula (G):

wherein R₁ is an isosorbide unit and R₂-R₉ are each independently ahydrogen, a halogen, a C₁-C₆ alkyl, a methoxy, an ethoxy, or an alkylester.

The R₁ isosorbide unit may be represented by Formula (G-a):

The isosorbide unit may be derived from an isosorbide, a mixture ofisosorbide, a mixture of isomers of isosorbide, and/or from individualisomers of isosorbide. The stereochemistry for the isosorbide-basedcarbonate units of Formula (I) is not particularly limited. These diolsmay be prepared by the dehydration of the corresponding hexitols.Hexitols are produced commercially from the corresponding sugars(aldohexose). Aliphatic diols include 1,4:3,6-dianhydro-D glucitol;1,4:3,6-dianhydro-D mannitol; and 1,4:3,6-dianhydro-L iditol; and anycombination thereof. Isosorbides are available commercially from variouschemical suppliers including Cargill, Roquette, and Shanxi. Theisosorbide-bisphenol may have a pKa of between 8 and 11.

As previously explained, a first photoactive moiety is reacted with afirst linker moiety, a polysiloxane monomer, and a diol chain extenderto obtain the photoactive additive. In some embodiments, a secondarylinker moiety is included in the reaction mixture. The secondary linkermoiety has at least three functional groups, each of which can reactwith the functional groups of the first linker moiety. Generally, thefunctional groups of the secondary linker moiety are hydroxyl groups.

Some examples of secondary linker moieties which have three functionalgroups and can react with the first linker moiety include those havingthe structure of one of Formulas (43)-(46):

Some examples of secondary linker moieties which have four functionalgroups and can react with the first linker moiety include those havingthe structure of one of Formulas (47)-(48):

In some embodiments, the secondary linker moiety can be an oligomer,made from an epoxidized novolac monomer. These oligomers can permit thedesired number of functional groups to be provided. Such oligomers aregeneralized by the structure of Formula (49):

wherein E is hydrogen or an endcapping agent; and t is an integer from 1to 20.

An end-capping agent is generally used to terminate any polymer chainsof the photoactive additive. The end-capping agent (i.e. chain stopper)is a monohydroxy compound, a mono-acid compound, or a mono-estercompound. Exemplary endcapping agents include phenol, p-cumylphenol(PCP), resorcinol monobenzoate, p-tert-butylphenol, octylphenol,p-cyanophenol, and p-methoxyphenol. If not modified with otheradjectives, the term “end-capping agent” is used herein to denote acompound that is not photoactive when exposed to light. For example, theend-capping agent does not contain a ketone group. The photoactiveadditive may comprise about 0.5 mole % to about 5.0 mole % endcap groupsderived from the end-capping agent.

However, in some embodiments, the end-capping agent can be a photoactiveend-capping agent, such as a monohydroxybenzophenone. Suitablemonohydroxybenzophenone end-capping agents include, but are not limitedto, 2-hydroxybenzophenone, 3-hydroxybenzophenone, 4-hydroxybenzophenone,4-hydroxybenzoylbenzophenone, 2-hydroxy-4-methoxybenzophenone,2-hydroxy-4-methoxy-2′-carboxybenzophenone,2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-stearoxybenzophenone,4-dodecyloxy-2-hydroxybenzophenone,2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, and2-hydroxy-4-methoxybenzophenone-5-sulfonic acid. In one preferredembodiment, the monohydroxybenzophenone chain stopper is a2-hydroxybenzophenone, 3-hydroxybenzophenone, or 4-hydroxybenzophenone,each of which may be further substituted with one or more additionalsubstituents, provided the monohydroxybenzophenone still functions as achain-stopper. In another preferred embodiment, themonohydroxybenzophenone is 4-hydroxybenzophenone.

The cross-linkable polycarbonates (also referred to as “non-cross-linkedpolycarbonates”) may comprise about 0.5 mole % to about 5 mole % endcapgroups derived from a monohydroxybenzophenone, about 1 mole % to about 3mole % endcap groups derived from a monohydroxybenzophenone, about 1.7mole % to about 2.5 mole % endcap groups derived from amonohydroxybenzophenone, about 2 mole % to about 2.5 mole % endcapgroups derived from a monohydroxybenzophenone, or about 2.5 mole % toabout 3.0 mole % endcap groups derived from a monohydroxybenzophenone.

Depending on the selection of the first linker moiety, the photoactiveadditive of the present disclosure may be a polyester-polycarbonatecopolymer. The molar ratio of ester units to carbonate units in thepolyester-polycarbonate may vary broadly, for example 1:99 to 99:1,specifically 10:90 to 90:10, more specifically 25:75 to 75:25,optionally expanded depending on the desired properties of the finalcomposition. The polyester units may be derived from an aliphatic oraromatic dicarboxylic acid. Aliphatic dicarboxylic acids may have from 6to about 36 carbon atoms, optionally from 6 to 20 carbon atoms.Exemplary aliphatic dicarboxylic acids include adipic acid, sebacicacid, 3,3-dimethyl adipic acid, 3,3,6-trimethyl sebacic acid,3,3,5,5-tetramethyl sebacic acid, azelaic acid, dodecanedioic acid,dimer acids, cyclohexane dicarboxylic acids, dimethyl cyclohexanedicarboxylic acid, norbornane dicarboxylic acids, adamantanedicarboxylic acids, cyclohexene dicarboxylic acids, or C₁₄, C₁₈ and C₂₀diacids. Exemplary aromatic dicarboxylic acids include isophthalic orterephthalic acid, 1,2-di(p-carboxyphenyl)ethane, 4,4′-dicarboxydiphenylether, 4,4′-bisbenzoic acid; 1,4-, 1,5-, or 2,6-naphthalenedicarboxylicacids; and combinations comprising at least one of the foregoing acids.A specific dicarboxylic acid mixture comprises a combination ofisophthalic acid and terephthalic acid wherein the weight ratio ofisophthalic acid to terephthalic acid is about 91:9 to about 2:98.

The polyester unit of a polyester-polycarbonate may be derived from thereaction of a combination of isophthalic and terephthalic diacids (orderivatives thereof) with resorcinol. In another embodiment, thepolyester unit of a polyester-polycarbonate may be derived from thereaction of a combination of isophthalic acid and terephthalic acid withbisphenol-A. In an embodiment, the polycarbonate units may be derivedfrom bisphenol-A. In another specific embodiment, the polycarbonateunits may be derived from resorcinol and bisphenol-A in a molar ratio ofresorcinol carbonate units to bisphenol-A carbonate units of 1:99 to99:1.

The photoactive additives of the present disclosure can be a compound,an oligomer, or a polymer. The oligomer has a weight average molecularweight (Mw) of less than 15,000, including 10,000 or less. The polymericphotoactive additives of the present disclosure have a Mw of 15,000 orhigher. In particular embodiments, the Mw is between 17,000 and 80,000Daltons, or between 17,000 and 35,000 Daltons. These molecular weightsare measured prior to any UV exposure. The Mw may be varied as desired.Polymers/oligomers with relatively higher Mw's generally retain theirmechanical properties better, while polymers/oligomers with relativelylower Mw's generally have better flow properties. In some particularembodiments, the Mw of the photoactive additives is about 5,000 or less.

In this regard, when the photoactive additives (PAA) are blended with apolymeric base resin and molded, it is desired to promote the migrationof the PAA to the air-polymer interface, i.e. the surface of thearticle. Upon exposure to the appropriate wavelength, crosslinking willoccur and result in a molded article having improved flame retardantproperties and chemical resistance.

Due to its very low surface energies (20-22 mN/m) and low solubilityparameters, the polysiloxane blocks in the PAA provided by thepolysiloxane monomer tends to phase separate in bulk and also migrate tothe air-polymer interface. The surface compositions and properties ofthe final molded article will depend on the amount and the block lengthof silicone in the polysiloxane monomer, the type and nature of the baseresin (e.g. amorphous or crystalline morphology), method of preparation,and annealing conditions.

FIG. 1 and FIG. 2 illustrate two photoactive additives of the presentdisclosure. These are exemplary, and are not intended to be limiting.These two figures all use a eugenol-endcapped polysiloxane monomer ofFormula (II). The full formula of that monomer is identified as Formula(II-a) below:

However, to reduce the space needed for the figures, this polysiloxanemonomer is abbreviated as:

In FIG. 1, the photoactive additive is a terpolymer formed from thereaction of p-cumylphenol (endcap), 4,4′-dihydroxybenzophenone(photoactive), bisphenol-A (chain extender), polysiloxane monomer, andphosgene (linker). The resulting additive contains carbonate linkages,and is an oligomer or polymer. It should be noted that this figure onlyshows the repeating units in their relative molar amounts (p, q, r), andshould not be construed as disclosing a specific block arrangement ofthe monomers.

In FIG. 2, the photoactive additive is a dipolymer formed from thereaction of 4-hydroxybenzophenone (photoactive endcap), polysiloxane,bisphenol-A (chain extender), and phosgene (linker). The resultingadditive contains carbonate linkages, and is an oligomer or polymer. Itshould be noted that this figure only shows the repeating units in theirrelative molar amounts (p, q), and should not be construed as disclosinga specific block arrangement of the monomers.

One crosslinking mechanism of the additives is believed to be due tohydrogen abstraction by the ketone group from an alkyl group that actsas a hydrogen donor and subsequent coupling of the resulting radicals.This mechanism is illustrated in FIG. 3 with reference to a benzophenone(the photoactive moiety) and a bisphenol-A (BPA) monomer. Upon exposureto UV, the oxygen atom of the benzophenone abstracts a hydrogen atomfrom a methyl group on the BPA monomer and becomes a hydroxyl group. Themethylene group then forms a covalent bond with the carbon of the ketonegroup. Put another way, the ketone group of the benzophenone could beconsidered to be a photoactive group. It should be noted that thepresence of an abstractable hydrogen is critical for this reaction tooccur. Other mechanisms may occur after the initial abstraction eventwith base resins containing unsaturated bonds or reactive side groups.

In particular embodiments, the photoactive additives (PAAs) disclosedherein are cross-linkable polycarbonate-polysiloxane copolymerscomprising repeating units derived from a dihydroxybenzophenone monomer(i.e. of Formula (17)). These polycarbonates, prior to cross-linking,can be provided as thermally stable high melt-flow polymers, and canthus be used to fabricate a variety of thin-walled products (e.g., 3 mmor less). These products may subsequently be treated (e.g., withUV-radiation) to affect cross-linking, thereby providing thin-walledmaterials that meet desired performance requirements (e.g., 5VAperformance, chemical resistance, transparency). The cross-linkedmaterials, in addition to flame resistance and chemical resistance, mayretain or exhibit superior mechanical properties (e.g., impactresistance, ductility) as compared to the composition prior tocross-linking.

The dihydroxybenzophenone monomers of the cross-linkable polycarbonatesprovide a photoactive ketone group for cross-linking the polycarbonates.Treatment of a cross-linkable polycarbonate of the present disclosurewith a suitable dose of UV radiation initiates a cross-linking reactionbetween the dihydroxybenzophenone carbonyl carbon and the carbon atom ofanother functional group (e.g., a methylene carbon atom, such as inbisphenol-A) in the same polymer or another polymer in the composition.

The cross-linkable polycarbonates of the present disclosure includehomopolycarbonates, copolymers comprising different moieties in thecarbonate (referred as “copolycarbonates”), copolymers comprisingcarbonate units and other types of polymer units such as polyesterunits, polysiloxane units, and combinations comprising at least onehomopolycarbonate and copolycarbonate. For reference, the term“dipolymer” refers to copolymers derived specifically from two differentmonomers, and the term “terpolymer” refers to copolymers derivedspecifically from three different monomers

Because the cross-linkable polycarbonate is a copolymer, the monomersmay be randomly incorporated into the polycarbonate. A random copolymermay have several block sequences and alternate sequences that follow astatistical distribution. In a random x:(1-x) copolymer, wherein x isthe mole percent of a first monomer and 1-x is the mole percent of theother monomers, one can calculate the distribution of each monomer usingpeak area values determined by ¹³C NMR, for example. The copolymer canbe an alternating copolymer with alternating I and O units(—I—O—I—O—I—O—I—O—), or I and O units arranged in a repeating sequence(e.g. a periodic copolymer having the formula:(I—O—I—O—O—I—I—I—O—O—O)n). The cross-linkable polycarbonate copolymermay be a statistical copolymer in which the sequence of monomer residuesfollows a statistical rule. The copolymer may also be a block copolymerthat comprises two or more homopolymer subunits linked by covalent bonds(—I—I—I—I—I—O—O—O—O—O—). The union of the homopolymer subunits mayrequire an intermediate non-repeating subunit, known as a junctionblock. Block copolymers with two or three distinct blocks are calleddiblock copolymers and triblock copolymers, respectively.

In embodiments, the cross-linkable polycarbonate-polysiloxane copolymersof the present disclosure contain from about 0.5 mole % to about 50 mole% of the dihydroxybenzophenone monomer (i.e. repeating units derivedfrom the dihydroxybenzophenone monomer). In more specific embodiments,the copolymers contain from about 1 mole % to about 3 mole %, or fromabout 1 mole % to about 6 mole %, from about 10 mole % to about 25 mole%%, or from about 0.5 mole % to about 25 mole % of thedihydroxybenzophenone monomer. The cross-linkablepolycarbonate-polysiloxane copolymers of the present disclosure containthe polysiloxane monomer in an amount such that the copolymer containsfrom about 1 wt % to about 25 wt % of siloxane units, or from about 1 wt% to about 10 wt % of siloxane units. The cross-linkablepolycarbonate-polysiloxane copolymers of the present disclosure alsocontain from about 50 mole % to about 95.5 mole % of the diol chainextender. In this regard, the polycarbonate-polysiloxane copolymers areusually terpolymers.

The cross-linkable polycarbonate-polysiloxane copolymers of the presentdisclosure may have a polydispersity index (PDI) of about 2.0 to about5.0, about 2.0 to about 3.0, or about 2.0 to about 2.5. The PDI ismeasured prior to any UV exposure.

It is noted that the molecular weight (both weight-average andnumber-average) of the photoactive additive/cross-linkablepolycarbonate-polysiloxane copolymer can be measured using two differentkinds of detectors. More specifically, the molecular weight can bemeasured using an ultraviolet (UV) detector or using a refractive index(RI) detector, using GPC and calibrated to polycarbonate standards forboth detectors.

The cross-linkable polycarbonate-polysiloxane copolymers of the presentdisclosure may have a melt flow rate (often abbreviated MFR), whichmeasures the rate of extrusion of a composition through an orifice at aprescribed temperature and load. In certain embodiments, thepolycarbonates may have an MFR of 6 to 15 grams/10 min, 6 to 8 grams/10min, 6 to 12 grams/10 min, 2 to 30 grams/10 min, 5 to 30 grams/10 min, 2to 100 grams/10 min, 8 to 12 grams/10 min, 8 to 10 grams/10 min, 20 to30 grams/10 min, 45 to 55 grams/10 min, or 75 to 100 grams/10 min, usingthe ASTM D1238 method, 1.2 kg load, 300° C. temperature, 360 seconddwell.

The cross-linkable polycarbonate-polysiloxane copolymers of the presentdisclosure may have a biocontent of 2 wt % to 90 wt %; 5 wt % to 25 wt%; 10 wt % to 30 wt %; 15 wt % to 35 wt %; 20 wt % to 40 wt %; 25 wt %to 45 wt %; 30 wt % to 50 wt %; 35 wt % to 55 wt %; 40 wt % to 60 wt %;45 wt % to 65 wt %; 55 wt % to 70% wt %; 60 wt % to 75 wt %; 50 wt % to80 wt %; or 50 wt % to 90 wt %. The biocontent may be measured accordingto ASTM D6866.

The cross-linkable polycarbonate-polysiloxane copolymers of the presentdisclosure may have a modulus of elasticity of greater than or equal to2200 megapascals (MPa), greater than or equal to 2310 MPa, greater thanor equal to 2320 MPa, greater than or equal to 2330 MPa, greater than orequal to 2340 MPa, greater than or equal to 2350 MPa, greater than orequal to 2360 MPa, greater than or equal to 2370 MPa, greater than orequal to 2380 MPa, greater than or equal to 2390 MPa, greater than orequal to 2400 MPa, greater than or equal to 2420 MPa, greater than orequal to 2440 MPa, greater than or equal to 2460 MPa, greater than orequal to 2480 MPa, greater than or equal to 2500 MPa, or greater than orequal to 2520 MPa as measured by ASTM D 790 at 1.3 mm/min, 50 mm span.

In embodiments, the cross-linkable polycarbonate-polysiloxane copolymersof the present disclosure may have a flexural modulus of 2,200 to 2,500,preferably 2,250 to 2,450, more preferably 2,300 to 2,400 MPa. In otherembodiments, the cross-linkable polycarbonates of the present disclosuremay have a flexural modulus of 2,300 to 2,600, preferably 2,400 to2,600, more preferably 2,450 to 2,550 MPa. The flexural modulus is alsomeasured by ASTM D790.

The cross-linkable polycarbonate-polysiloxane copolymers of the presentdisclosure may have a tensile strength at break of greater than or equalto 60 megapascals (MPa), greater than or equal to 61 MPa, greater thanor equal to 62 MPa, greater than or equal to 63 MPa, greater than orequal to 64 MPa, greater than or equal to 65 MPa, greater than or equalto 66 MPa, greater than or equal to 67 MPa, greater than or equal to 68MPa, greater than or equal to 69 MPa, greater than or equal to 70 MPa,greater than or equal to 71 MPa, greater than or equal to 72 MPa,greater than or equal to 73 MPa, greater than or equal to 74 MPa,greater than or equal to 75 MPa as measured by ASTM D 638 Type I at 50mm/min.

The cross-linkable polycarbonate-polysiloxane copolymers of the presentdisclosure may possess a ductility of greater than or equal to 60%,greater than or equal to 65%, greater than or equal to 70%, greater thanor equal to 75%, greater than or equal to 80%, greater than or equal to85%, greater than or equal to 90%, greater than or equal to 95%, or 100%in a notched izod test at −20° C., −15° C., −10° C., 0° C., 5° C., 10°C., 15° C., 20° C., 23° C., 25° C., 30° C., or 35° C. at a thickness of3.2 mm according to ASTM D 256-10.

The cross-linkable polycarbonate-polysiloxane copolymers of the presentdisclosure may have a notched Izod impact strength (NII) of greater thanor equal to 500 J/m, greater than or equal to 550 J/m, greater than orequal to 600 J/m, greater than or equal to 650 J/m, greater than orequal to 700 J/m, greater than or equal to 750 J/m, greater than orequal to 800 J/m, greater than or equal to 850 J/m, greater than orequal to 900 J/m, greater than or equal to 950 J/m, or greater than orequal to 1000 J/m, measured at 23° C. according to ASTM D 256.

The cross-linkable polycarbonate-polysiloxane copolymers of the presentdisclosure may have a heat distortion temperature of greater than orequal to 110° C., 111° C., 112° C., 113° C., 114° C., 115° C., 116° C.,117° C., 118° C., 119° C., 120° C., 121° C., 122° C., 123° C., 124° C.,125° C., 126° C., 127° C., 128° C., 129° C., 130° C., 131° C., 132° C.,133° C., 134° C., 135° C., 136° C., 137° C., 138° C., 139° C., 140° C.,141° C., 142° C., 143° C., 144° C., 145° C., 146° C., 147° C., 148° C.,149° C., 150° C., 151° C., 152° C., 153° C., 154° C., 155° C., 156° C.,157° C., 158° C., 159° C., 160, 161° C., 162° C., 163° C., 164° C., 165°C., 166° C., 167° C., 168° C., 169° C., or 170° C., as measuredaccording to ASTM D 648 at 1.82 MPa, with 3.2 mm thick unannealed mmbar.

The cross-linkable polycarbonate-polysiloxane copolymers of the presentdisclosure may have a percent haze value of less than or equal to 10.0%,less than or equal to 8.0%, less than or equal to 6.0%, less than orequal to 5.0%, less than or equal to 4.0%, less than or equal to 3.0%,less than or equal to 2.0%, less than or equal to 1.5%, less than orequal to 1.0%, or less than or equal to 0.5% as measured at a certainthickness according to ASTM D 1003-07. The polycarbonate haze may bemeasured at a 2.0, 2.2, 2.4, 2.54, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, ora 4.0 millimeter thickness. The polycarbonate may be measured at a 0.125inch thickness.

The polycarbonate-polysiloxane copolymers may have a light transmittancegreater than or equal to 50%, greater than or equal to 60%, greater thanor equal to 65%, greater than or equal to 70%, greater than or equal to75%, greater than or equal to 80%, greater than or equal to 85%, greaterthan or equal to 90%, greater than or equal to 95%, greater than orequal to 96%, greater than or equal to 97%, greater than or equal to98%, greater than or equal to 99%, greater than or equal to 99.1%,greater than or equal to 99.2%, greater than or equal to 99.3%, greaterthan or equal to 99.4%, greater than or equal to 99.5%, greater than orequal to 99.6%, greater than or equal to 99.7%, greater than or equal to99.8%, or greater than or equal to 99.9%, as measured at certainthicknesses according to ASTM D 1003-07. The polycarbonate transparencymay be measured at a 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8,or a 4.0 millimeter thickness.

In particular embodiments, the photoactive cross-linkablepolycarbonate-polysiloxane copolymer is formed from adihydroxybenzophenone, a polysiloxane monomer, a diol chain extender,phosgene, and one or more end-capping agents. Most desirably, thedihydroxybenzophenone is 4,4′-dihydroxybenzophenone. In preferredembodiments, the diol chain extender is bisphenol-A, and the end-cappingagent is p-cumylphenol. The resulting photoactive additive (i.e.cross-linkable polycarbonate-polysiloxane copolymer) can comprise fromabout 0.5 mole % to 50 mole % of the dihydroxybenzophenone; from about50 mole % to about 95.5 mole % of the diol chain extender; and an amountof the polysiloxane monomer sufficient to provide 1 wt % to 25 wt % ofsiloxane to the additive.

Processes

An interfacial polycondensation polymerization process for bisphenol-A(BPA) based polycarbonates can be used to prepare the photoactiveadditives (PAAs) of the present disclosure. Although the reactionconditions for interfacial polymerization can vary, an exemplary processgenerally involves dissolving or dispersing one or more dihydric phenolreactants (e.g. the dihydroxybenzophenone, polysiloxane monomer,bisphenol-A) in water, adding the resulting mixture to awater-immiscible solvent medium, and contacting the reactants with acarbonate precursor (e.g. phosgene) in the presence of a catalyst (e.g.triethylamine, TEA).

Four different processes are disclosed herein for producing someembodiments of the photoactive additive which contain carbonatelinkages. Each process includes the following ingredients: adihydroxybenzophenone, a diol chain extender, an end-capping agent, acarbonate precursor, a base, a tertiary amine catalyst, water, and awater-immiscible organic solvent, and optionally a branching agent. Thedihydroxybenzophenone is the photoactive moiety. It should be noted thatmore than one of each ingredient can be used to produce the photoactiveadditive. Many of these ingredients have been previously described.

The carbonate precursor may be, for example, a carbonyl halide such ascarbonyl dibromide or carbonyl dichloride (also known as phosgene), or ahaloformate such as a bishaloformate of a dihydric phenol (e.g., thebischloroformate of bisphenol-A, hydroquinone, or the like) or a glycol(e.g., the bishaloformate of ethylene glycol, neopentyl glycol,polyethylene glycol, or the like). Combinations comprising at least oneof the foregoing types of carbonate precursors can also be used. Incertain embodiments, the carbonate precursor is phosgene, a triphosgene,diacyl halide, dihaloformate, dicyanate, diester, diepoxy,diarylcarbonate, dianhydride, diacid chloride, or any combinationthereof. An interfacial polymerization reaction to form carbonatelinkages may use phosgene as a carbonate precursor, and is referred toas a phosgenation reaction. Many such carbonate precursors correspond toa structure of Formulas (30), (32), or (33).

The base is used for the regulation of the pH of the reaction mixture.In particular embodiments, the base is an alkali metal hydroxide, suchas sodium hydroxide (NaOH) or potassium hydroxide (KOH).

A tertiary amine catalyst is used for polymerization. Exemplary tertiaryamine catalysts that can be used are aliphatic tertiary amines such astriethylamine (TEA), N-ethylpiperidine, 1,4-diazabicyclo[2.2.2]octane(DABCO), tributylamine, cycloaliphatic amines such asN,N-diethyl-cyclohexylamine and aromatic tertiary amines such as N,N-dimethyl aniline.

Sometimes, a phase transfer catalyst is also used. Among the phasetransfer catalysts that can be used are catalysts of the formula(R³⁰)₄Q⁺X, wherein each R³⁰ is the same or different, and is a C₁-C₁₀alkyl group; Q is a nitrogen or phosphorus atom; and X is a halogenatom, C₁-C₈ alkoxy group, or C₆-C₁₈ aryloxy group. Exemplary phasetransfer catalysts include, for example, [CH₃(CH₂)₃]₄NX, [CH₃(CH₂)₃]₄PX,[CH₃(CH₂)₅]₄NX, [CH₃(CH₂)₆]₄NX, [CH₃(CH₂)₄]₄NX, CH₃[CH₃(CH₂)₃]₃NX, andCH₃[CH₃(CH₂)₂]₃NX, wherein X is Cl⁻, Br⁻, a C₁-C₈ alkoxy group or aC₆-C₁₈ aryloxy group, such as methyltributylammonium chloride.

The most commonly used water-immiscible solvents include methylenechloride, 1,2-dichloroethane, chlorobenzene, toluene, and the like.

In the first process, sometimes referred to as the “upfront” process,the dihydroxybenzophenone, diol chain extender, end-capping agent,catalyst, water, and water-immiscible solvent are combined upfront in avessel to form a reaction mixture. The reaction mixture is then exposedto the carbonate precursor, for example by phosgenation, while the baseis co-added to regulate the reaction pH, to obtain the photoactiveadditive.

In the second process, also known as the “solution addition” process,the dihydroxybenzophenone, diol chain extender, tertiary amine catalyst,water, and water-immiscible solvent are combined in a vessel to form areaction mixture. The total charge of the carbonate precursor is thenadded to this reaction mixture in the vessel over a total time period ofabout 15 minutes to about 45 minutes, while the base is co-added toregulate the pH. The carbonate precursor is first added to the reactionmixture along with the base to regulate the pH for a first time periodthat ranges from about 2 minutes to about 20 minutes. After the firsttime period ends, the end-capping agent is added in a controlled mannerto the reaction mixture, also referred to as programmed addition. Theaddition of the end-capping agent occurs for a second time period afterthe first time period, rather than as a bolus at the beginning of thereaction (as in the upfront process). The carbonate precursor and thebase are also added concurrently with the end-capping agent during thesecond time period. After the second time period ends, the remainder ofthe carbonate precursor continues uninterrupted for a third time perioduntil the total charge is reached. The base is also co-added during thethird time period to regulate the reaction pH. The end-capping agent isnot added during either the first time period or the third time period.The photoactive additive is thus obtained. The total time period for thereaction is the sum of the first time period, the second time period,and the third time period. In particular embodiments, the second timeperiod in which the solution containing the end-capping agent is addedto the reaction mixture begins at a point between 10% to about 40% ofthe total time period. Put another way, the first time period is 10% ofthe total time period.

The third process is also referred to as a bis-chloroformate orchloroformate (BCF) process. Chloroformate oligomers are prepared byreacting the carbonate precursor, specifically phosgene, with thedihydroxybenzophenone and the diol chain extender in the absence of thetertiary amine catalyst, while the base is co-added to regulate the pH.The chloroformate oligomers can contain a mixture of monochloroformates,bischloroformates, and bisphenol terminated oligomers. After thechloroformate oligomers are generated, the phosgene can optionally beallowed to substantially condense or hydrolyze, then the end-cappingagent is added to the chloroformate mixture. The reaction is allowed toproceed, and the tertiary amine catalyst is added to complete thereaction.

The fourth process uses a tubular reactor. In the tubular reactor, theend-capping agent is pre-reacted with the carbonate precursor(specifically phosgene) to form chloroformates. The water-immisciblesolvent is used as a solvent in the tubular reactor. In a separatereactor, the dihydroxybenzophenone, diol chain extender, tertiary aminecatalyst, water, and water-immiscible solvent are combined to form areaction mixture. The chloroformates in the tubular reactor are then fedinto the reactor over a first time period along with additionalcarbonate precursor to complete the reaction while the base is co-addedto regulate the pH.

In certain embodiments, a combination of the solution addition and thetubular reactor processes is used. A solution of the polysiloxanemonomer is made in a first tank, and a solution of the end-cappingagent/monohydroxybenzophenone (when used) is made in a second tank. In aseparate reactor, the dihydroxybenzophenone (when used), diol chainextender, tertiary amine catalyst, water, and water-immiscible solventare combined to form a reaction mixture. The carbonate precursor isfirst added to the reaction mixture along with the base to regulate thepH for a first time period that ranges from about 2 minutes to about 20minutes. After the first time period ends, the end-capping agent isadded in a controlled manner to the reaction mixture. Concurrently, anamount of the carbonate precursor is charged to the first tankcontaining the polysiloxane monomer. This forms chloroformates, and thefirst tank is fed into the reaction mixture as well. The addition of theend-capping agent and the polysiloxane monomer occurs for a second timeperiod after the first time period. The carbonate precursor and the baseare also added concurrently during the second time period. After thesecond time period ends, the end-capping agent and the polysiloxanechloroformates have been added to the reaction mixture. While theaddition of the end-capping agent and the polysiloxane chloroformatesbegin roughly concurrently, they usually do not end concurrently. Afterthe second time period ends, the remainder of the carbonate precursorcontinues uninterrupted for a third time period until the total chargeis reached. The base is also co-added during the third time period toregulate the reaction pH. The end-capping agent and polysiloxane are notadded during either the first time period or the third time period. Thephotoactive additive is thus obtained.

The resulting photoactive additive (e.g. the cross-linkablepolycarbonate) contains only a small amount of low-molecular-weightcomponents. This can be measured in two different ways: the level ofdiarylcarbonates (DAC) and the lows percentage can be measured.Diarylcarbonates are formed by the reaction of two end-capping agentswith phosgene, creating a small molecule that contains nodihydroxybenzophenone or diol chain extender (e.g. bisphenol-A). Inembodiments, the resulting photoactive additive contains less than 1000ppm of diarylcarbonates. The lows percentage is the percentage by weightof oligomeric chains having a molecular weight of less than 1000. Inembodiments, the lows percentage is 2.0 wt % or less, including fromabout 1.0 wt % to 2.0 wt %. The DAC level and the lows percentage can bemeasured by high performance liquid chromatography (HPLC) or gelpermeation chromatography (GPC). Also of note is that the resultingphotoactive additive does not contain any residual pyridine, becausepyridine is not used in the manufacture of the photoactive additive.

Second Polymer Resin

The PAAs can be blended with a polymeric base resin that is differentfrom the photoactive additive, i.e. a second polymer resin, to form thepolymeric compositions/blends of the present disclosure. Morespecifically, the second polymer resin does not contain photoactivegroups. The amount of PAA added to the blend can be used to fine-tunethe final properties of the article. For example, products requiringhigh chemical resistance and FR drip inhibition would need increased PAAcontent. In embodiments, the weight ratio of the photoactive additive tothe polymeric base resin is from 1:99 to 99:1, including from about50:50 to about 85:15, or from about 10:90 to about 15:85, or from about25:75 to about 50:50. The polymeric base resin has, in specificembodiments, a weight-average molecular weight of about 21,000 orgreater, including from about 21,000 to about 40,000. The PAAs aresuitable for blending with polycarbonate homopolymers, polycarbonatecopolymers, and polycarbonate blends. They are also suitable forblending with polyesters, polyarylates, polyestercarbonates, andpolyetherimides.

The blends may be subjected to cross-linking conditions (e.g.,UV-radiation) to affect cross-linking of the photoactive additives inthe blend. Accordingly, blend compositions of the present disclosureinclude blends prior to and after cross-linking.

The blends may comprise one or more distinct cross-linkablepolycarbonates, as described herein, and/or one or more cross-linkedpolycarbonates, as described herein, as the photoactive additive. Theblends also comprise one or more additional polymers. The blends maycomprise additional components, such as one or more additives. Incertain embodiments, a blend comprises a cross-linkable and/orcross-linked polycarbonate (Polymer A) and a second polymer (Polymer B),and optionally one or more additives. In another embodiment, a blendcomprises a combination of a cross-linkable and/or cross-linkedpolycarbonate (Polymer A); and a second polycarbonate (Polymer B),wherein the second polycarbonate is different from the firstpolycarbonate.

In a preferred embodiment, the blend compositions disclosed hereincomprise a flame-retardant, a flame retardant additive, and/or an impactmodifier. The flame-retardant may be potassium perfluorobutane sulfonate(Rimar salt), potassium diphenyl sulfone-3-sulfonate (KSS), or acombination thereof.

The second polymer (Polymer B) may be any polymer different from thefirst polymer that is suitable for use in a blend composition. Incertain embodiments, the second polymer may be a polyester, apolyestercarbonate, a bisphenol-A homopolycarbonate, a polycarbonatecopolymer, a tetrabromo-bisphenol A polycarbonate copolymer, apolysiloxane-co-bisphenol-A polycarbonate, a polyesteramide, apolyimide, a polyetherimide, a polyamideimide, a polyether, apolyethersulfone, a polyepoxide, a polylactide, a polylactic acid (PLA),or any combination thereof.

In certain embodiments, the second polymer may be a vinyl polymer, arubber-modified graft copolymer, an acrylic polymer, polyacrylonitrile,a polystyrene, a polyolefin, a polyester, a polyesteramide, apolysiloxane, a polyurethane, a polyamide, a polyamideimide, apolysulfone, a polyepoxide, a polyether, a polyimide, a polyetherimide,a polyphenylene ether, a polyphenylene sulfide, a polyether ketone, apolyether ether ketone, an acrylonitrile-butadiene-styrene (ABS) resin,an acrylic-styrene-acrylonitrile (ASA) resin, a polyethersulfone, apolyphenylsulfone, a poly(alkenylaromatic) polymer, a polybutadiene, apolyacetal, a polycarbonate, a polyphenylene ether, an ethylene-vinylacetate copolymer, a polyvinyl acetate, a liquid crystal polymer, anethylene-tetrafluoroethylene copolymer, an aromatic polyester, apolyvinyl fluoride, a polyvinylidene fluoride, a polyvinylidenechloride, tetrafluoroethylene, a polylactide, a polylactic acid (PLA), apolycarbonate-polyorganosiloxane block copolymer, or a copolymercomprising: (i) an aromatic ester, (ii) an estercarbonate, and (iii)carbonate repeat units. The blend composition may comprise additionalpolymers (e.g. a third, fourth, fifth, sixth, etc., polymer).

In certain embodiments, the second polymer may be a homopolycarbonate, acopolycarbonate, a polycarbonate-polysiloxane copolymer, apolyester-polycarbonate, or any combination thereof. In certainembodiments, the second polycarbonate is a p-cumyl phenol cappedpoly(isophthalate-terephthalate-resorcinol ester)-co-(bisphenol-Acarbonate) copolymer. In certain embodiments, the second polycarbonateis a polycarbonate-polysiloxane copolymer.

The p-cumyl phenol capped poly(isophthalate-terephthalate-resorcinolester)-co-(bisphenol-A carbonate) polymer or apolycarbonate-polysiloxane copolymer may have a polysiloxane contentfrom 0.4 wt % to 25 wt %. In one preferred embodiment, the secondpolymer is a p-cumylphenol capped poly (19 mol %isophthalate-terephthalate-resorcinol ester)-co-(75 mol % bisphenol-Acarbonate)-co-(6 mol % resorcinol carbonate) copolymer (MW=29,000Daltons). In another preferred embodiment, the second polymer is ap-cumylphenol capped poly(10 wt % isophthalate-terephthalate-resorcinolester)-co-(87 wt % bisphenol-A carbonate)-co-(3 mol % resorcinolcarbonate) copolymer (MW=29,000 Daltons).

In another preferred embodiment, the second polymer is a polycarbonatepolysiloxane copolymer. The polycarbonate-polysiloxane copolymer may bea siloxane block co-polycarbonate comprising from about 6 wt % siloxane(±10%) to about 20 wt % siloxane (±10%), and having a siloxane chainlength of 10 to 200. In another preferred embodiment, the second polymeris a PC-siloxane copolymer with 20% siloxane segments by weight. Inanother preferred embodiment, the second polymer is a p-cumylphenolcapped poly (65 mol % BPA carbonate)-co-(35 mol %3,3-bis(4-hydroxyphenyl)-2-phenylisoindolin-1-one (PPPBP) carbonate)copolymer (MW=25,000 Daltons).

In another preferred embodiment, the second polymer is a polyphosphonatepolymer, a polyphosphonate copolymer, or a poly(polyphosphonate)-co-(BPAcarbonate) copolymer.

In yet other embodiments, the polymer resin in the blend is selectedfrom the group consisting of a polycarbonate-polysiloxane copolymer; apolycarbonate resin having an aliphatic chain containing at least twocarbon atoms as a repeating unit in the polymer backbone; a copolyesterpolymer; a bisphenol-A homopolycarbonate; a polystyrene polymer; apoly(methyl methacrylate) polymer; a thermoplastic polyester; apolybutylene terephthalate polymer; a methylmethacrylate-butadiene-styrene copolymer; anacrylonitrile-butadiene-styrene copolymer; a dimethyl bisphenolcyclohexane-co-bisphenol-A copolymer; a polyetherimide; apolyethersulfone; and a copolycarbonate of bisphenol-A and1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane) (BPTMC).

Other Additives

Other conventional additives can also be added to the polymericcomposition (e.g. an impact modifier, UV stabilizer, colorant, flameretardant, heat stabilizer, plasticizer, lubricant, mold release agent,filler, reinforcing agent, antioxidant agent, antistatic agent, blowingagent, or radiation stabilizer).

In preferred embodiments, the blend compositions disclosed hereincomprise a flame-retardant, a flame retardant additive, and/or an impactmodifier. The flame-retardant may be potassium perfluorobutane sulfonate(Rimar salt), potassium diphenyl sulfone-3-sulfonate (KSS), or acombination thereof.

Various types of flame retardants can be utilized as additives. In oneembodiment, the flame retardant additives include, for example, flameretardant salts such as alkali metal salts of perfluorinated C₁-C₁₆alkyl sulfonates such as potassium perfluorobutane sulfonate (Rimarsalt), potassium perfluoroctane sulfonate, tetraethylammoniumperfluorohexane sulfonate, potassium diphenylsulfone sulfonate (KSS),and the like, sodium benzene sulfonate, sodium toluene sulfonate (NATS)and the like; and salts formed by reacting for example an alkali metalor alkaline earth metal (for example lithium, sodium, potassium,magnesium, calcium and barium salts) and an inorganic acid complex salt,for example, an oxo-anion, such as alkali metal and alkaline-earth metalsalts of carbonic acid, such as Na₂CO₃, K₂CO₃, MgCO₃, CaCO₃, and BaCO₃or fluoro-anion complex such as Li₃AlF₆, BaSiF₆, KBF₄, K₃AlF₆, KAlF₄,K₂SiF₆, and/or Na₃AlF₆ or the like. Rimar salt and KSS and NATS, aloneor in combination with other flame retardants, are particularly usefulin the compositions disclosed herein. In certain embodiments, the flameretardant does not contain bromine or chlorine.

The flame retardant optionally is a non-halogen based metal salt, e.g.,of a monomeric or polymeric aromatic sulfonate or mixture thereof. Themetal salt is, for example, an alkali metal or alkali earth metal saltor mixed metal salt. The metals of these groups include sodium, lithium,potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium,francium and barium. Examples of flame retardants include cesiumbenzenesulfonate and cesium p-toluenesulfonate. See e.g., U.S. Pat. No.3,933,734, EP 2103654, and US2010/0069543A1, the disclosures of whichare incorporated herein by reference in their entirety.

Another useful class of flame retardant is the class of cyclic siloxaneshaving the general formula [(R)₂SiO]_(y) wherein R is a monovalenthydrocarbon or fluorinated hydrocarbon having from 1 to 18 carbon atomsand y is a number from 3 to 12. Examples of fluorinated hydrocarboninclude, but are not limited to, 3-fluoropropyl, 3,3,3-trifluoropropyl,5,5,5,4,4,3,3-heptafluoropentyl, fluorophenyl, difluorophenyl andtrifluorotolyl. Examples of suitable cyclic siloxanes include, but arenot limited to, octamethylcyclotetrasiloxane,1,2,3,4-tetramethyl-1,2,3,4-tetravinylcyclotetrasiloxane,1,2,3,4-tetramethyl-1,2,3,4-tetraphenylcyclotetrasiloxane,octaethylcyclotetrasiloxane, octapropylcyclotetrasiloxane,octabutylcyclotetrasiloxane, decamethylcyclopentasiloxane,dodecamethylcyclohexasiloxane, tetradecamethylcycloheptasiloxane,hexadecamethylcyclooctasiloxane, eicosamethylcyclodecasiloxane,octaphenylcyclotetrasiloxane, and the like. A particularly useful cyclicsiloxane is octaphenylcyclotetrasiloxane.

Exemplary heat stabilizer additives include, for example,organophosphites such as triphenyl phosphite,tris-(2,6-dimethylphenyl)phosphite, tris-(mixed mono- anddi-nonylphenyl)phosphite or the like; phosphonates such asdimethylbenzene phosphonate or the like; phosphates such as trimethylphosphate, or the like; or combinations comprising at least one of theforegoing heat stabilizers. Heat stabilizers are generally used inamounts of 0.0001 to 1 part by weight, based on 100 parts by weight ofthe polymer component of the polymeric blend/composition.

Mold release agent (MRA) will allow the material to be removed quicklyand effectively. Mold releases can reduce cycle times, defects, andbrowning of finished product. There is considerable overlap among thesetypes of materials, which may include, for example, phthalic acid esterssuch as dioctyl-4,5-epoxy-hexahydrophthalate;tris-(octoxycarbonylethyl)isocyanurate; tristearin; di- orpolyfunctional aromatic phosphates such as resorcinol tetraphenyldiphosphate (RDP), the bis(diphenyl)phosphate of hydroquinone and thebis(diphenyl)phosphate of bisphenol-A; poly-alpha-olefins; epoxidizedsoybean oil; silicones, including silicone oils; esters, for example,fatty acid esters such as alkyl stearyl esters, e.g., methyl stearate,stearyl stearate, pentaerythritol tetrastearate (PETS), and the like;combinations of methyl stearate and hydrophilic and hydrophobic nonionicsurfactants comprising polyethylene glycol polymers, polypropyleneglycol polymers, poly(ethylene glycol-co-propylene glycol) copolymers,or a combination comprising at least one of the foregoing glycolpolymers, e.g., methyl stearate and polyethylene-polypropylene glycolcopolymer in a suitable solvent; waxes such as beeswax, montan wax,paraffin wax, or the like. Such materials are generally used in amountsof 0.001 to 1 part by weight, specifically 0.01 to 0.75 part by weight,more specifically 0.1 to 0.5 part by weight, based on 100 parts byweight of the polymer component of the polymeric blend/composition.

In particular embodiments, the polymeric blend/composition includes thephotoactive additive, an optional polymeric base resin, and a flameretardant which is Rimar salt and which is present in an amount of about0.05 wt % to about 0.085 wt %, based on the total weight of thecomposition; and a plaque comprising the polymeric composition has atransparency of 70 to 90% at a thickness of 3.2 mm, measured accordingto ASTM-D1003-00.

In other particular embodiments, the polymeric blend/compositionincludes the photoactive additive, an optional polymeric base resin, aflame retardant; a heat stabilizer, and a mold release agent.

The additives, when used, can improve the chemical resistance of thefinal product. It is contemplated that products can be of any desiredshape (e.g. molded article, film, sheet, etc.) and be used in manydifferent applications, for example in the medical, automotive, andconsumer electronics fields. Increased chemical resistance may be foundagainst 409 Glass and Surface Cleaner; Alcohol Prep Pad; CaviCideliquid/CaviWipes; CaviWipes; Cidex Plus liquid; Clorox Bleach; CloroxWipes; Envirocide liquid; For Pro liquid; Gentle dish soap and water;Hydrogen Peroxide Cleaner Disinfectant Wipes; Isopropyl Alcohol wipes;MadaCide-1 liquid; Mar-V-Cide liquid to dilute; Sani-Cloth Bleach Wipes;Sani-Cloth HB Wipes; Sani-Cloth Plus Wipes; Sodium Hypochlorite liquid;Super Sani-Cloth Wipes; Viraguard liquid and Wipes; Virex 256; WindexBlue; Fuel C; Toluene; Heptane; Ethanol; Isopropanol; Windex; Engineoil; WD40; Transmission fluid; Break fluid; Glass wash; Diesel;Gasoline; Banana Boat Sunscreen (SPF 30); Sebum; Ivory Dish Soap; SCJohnson Fantastik Cleaner; French's Yellow Mustard; Coca-Cola; 70%Isopropyl Alcohol; Extra Virgin Olive Oil; Vaseline Intensive Care HandLotion; Heinz Ketchup; Kraft Mayonnaise; Chlorox Formula 409 Cleaner; SCJohnson Windex Cleaner with Ammonia; Acetone; Artificial Sweat; Fruits &Passion Cucina Coriander & Olive Hand Cream; Loreal Studioline MegagelHair Gel; Maybelline Lip Polish; Maybelline Expert Wear Blush—Beach PlumRouge; Purell Hand Sanitizer; Hot coffee, black; iKlear; Chlorox Wipes;Squalene; Palmitic Acid; Oleic Acid; Palmitoleic Acid; Stearic Acid; andOlive Oil.

Products

Compositions/blends disclosed herein, preferably prior to cross-linking,may be formed, shaped, molded, injection molded, or extruded into aproduct, particularly thin-walled products, including highly transparentthin-walled products, having improved flame retardance and good physicalproperties. products

The compositions/blends can be molded into useful shaped products by avariety of means such as injection molding, overmolding, co-injectionmolding, extrusion, multilayer extrusion, rotational molding, blowmolding and thermoforming to form products. The formed products may besubsequently subjected to cross-linking conditions (e.g., UV-radiation)to affect cross-linking of the polycarbonates comprisingmonohydroxybenzophenone derived endcap. Exemplary products include afilm, a sheet, a layer of a multilayer film, or a layer of a multilayersheet.

Products that may be formed from the compositions/blends include variouscomponents for cell phones and cell phone covers, components forcomputer housings (e.g. mouse covers), fibers, computer housings andbusiness machine housings and parts such as housings and parts formonitors, computer routers, copiers, desk top printers, largeoffice/industrial printers handheld electronic device housings such ascomputer or business machine housings, housings for hand-held devices,components for light fixtures or home or office appliances, humidifierhousings, thermostat control housings air conditioner drain pans,outdoor cabinets, telecom enclosures and infrastructure, Simple NetworkIntrusion Detection System (SNIDS) devices, network interface devices,smoke detectors, components and devices in plenum spaces, components formedical applications or devices such as medical scanners, X-rayequipment, and ultrasound devices, components for interior or exteriorcomponents of an automobile, lenses (auto and non-auto) such ascomponents for film applications, greenhouse components, sun roomcomponents, fire helmets, safety shields, safety goggles, glasses withimpact resistance, fendors, gas pumps, films for televisions, such asecofriendly films having no halogen content, solar applicationmaterials, glass lamination materials, fibers for glass-filled systems,hand held electronic device enclosures or parts (e.g. walkie-talkie,scanner, media/MP3/MP4 player, radio, GPS system, ebook, tablet),wearable electronic devices (e.g. smart watch, training/tracking device,activity/sleep monitoring system, wristband, or glasses), hand held toolenclosures or parts, smart phone enclosures or parts, turbine blades(e.g., wind turbines), and the like.

In certain embodiments, products that may comprise the composition/blendinclude automotive bumpers, other automotive, construction andagricultural equipment exterior components, automobile mirror housings,an automobile grille, an automobile pillar, automobile wheel covers,automobile, construction and agricultural equipment instrument panelsand trim, construction and agricultural grilles, automobile glove boxes,automobile door hardware and other interior trim, automobileconstruction and agricultural equipment exterior lights, automobileparts within the engine compartment, plumbing equipment, valves andpumps, air conditioning heating and cooling parts, furnace and heat pumpparts, computer parts, electronics parts, projector parts, electronicdisplay parts, copier parts, scanner parts, electronic printer tonercartridges, hair driers, irons, coffee makers, toasters, washingmachines, microwaves, ovens, power tools, electric components, lightingparts, dental instruments and equipment, medical instruments, cookware,medical instrument trays, animal cages, fibers, laser welded medicaldevices, hand held electronic device enclosures or parts (e.g.walkie-talkie, scanner, media/MP3/MP4 player, radio, GPS system, ebook,tablet), wearable electronic devices (e.g. smart watch,training/tracking device, activity/sleep monitoring system, wristband,or glasses), hand held tool enclosures or parts, smart phone enclosuresor parts, and fiber optics.

In certain embodiments, products that may comprise the composition/blendinclude automotive bumpers, other automotive exterior components,automobile mirror housings, an automobile grille, an automobile pillar,automobile wheel covers, automobile instrument panels and trim,automobile glove boxes, automobile door hardware and other interiortrim, external automobile trim parts, such as pillars, automobileexterior lights, automobile parts within the engine compartment, anagricultural tractor or device part, a construction equipment vehicle ordevice part, a construction or agricultural equipment grille, a marineor personal water craft part, an all terrain vehicle or all terrainvehicle part, plumbing equipment, valves and pumps, air conditioningheating and cooling parts, furnace and heat pump parts, computer parts,electronics parts, projector parts, electronic display parts, copierparts, scanner parts, electronic printer toner cartridges, hair driers,irons, coffee makers, toasters, washing machines, microwaves, ovens,power tools, electric components, electric enclosures, lighting parts,dental instruments, medical instruments, medical or dental lightingparts, an aircraft part, a train or rail part, a seating component,sidewalls, ceiling parts, cookware, medical instrument trays, animalcages, fibers, laser welded medical devices, fiber optics, lenses (autoand non-auto), cell phone parts, greenhouse components, sun roomcomponents, fire helmets, safety shields, safety glasses, gas pumpparts, hand held electronic device enclosures or parts (e.g.walkie-talkie, scanner, media/MP3/MP4 player, radio, GPS system, ebook,tablet), wearable electronic devices (e.g. smart watch,training/tracking device, activity/sleep monitoring system, wristband,or glasses), hand held tool enclosures or parts, smart phone enclosuresor parts, and turbine blades.

In certain embodiments, the product is one that requires or must includea material having a UL94 5VA rating performance. Products that require aUL94 5VA rating include, but are not limited to, computer housings,computer housings and business machine housings and parts such ashousings and parts for monitors, computer routers, copiers, desk topprinters, large office/industrial printers, handheld electronic devicehousings such as computer or business machine housings, housings forhand-held devices, components for light fixtures including LED fixturesor home or office appliances, humidifier housings, thermostat controlhousings, air conditioner drain pans, outdoor cabinets, telecomenclosures and infrastructure, Simple Network Intrusion Detection System(SNIDS) devices, network interface devices, smoke detectors, componentsand devices in plenum spaces, components for medical applications ordevices such as medical scanners, X-ray equipment, and ultrasounddevices, electrical boxes and enclosures, and electrical connectors.

In certain embodiments, the product is one that requires hydrothermalstability, such as a wind turbine blade, a steam sterilizable medicaldevice, a food service tray, utensils and equipment.

In certain embodiments, the product is one that requires a combinationof transparency, flame resistance, and/or impact resistance. Forexample, in certain embodiments the product may be a safety shield,safety goggles, a gas/fuel pump housing, a display window or part, orthe like.

Ultraviolet Irradiation

The photoactive additive (PAA) can be blended with one or more polymericbase resins by melt blending or solution blending to form a polymericcomposition/blend. The PAA-containing blend can be then be formed into aproduct by a variety of known processes such as solution casting,profile extrusion, film and/or sheet extrusion, sheet-foam extrusion,injection molding, blow molding, thermoforming, and the like. Theproduct is then exposed to ultraviolet (UV) light at an appropriatewavelength and in an appropriate dosage that brings about the desiredamount of crosslinking for the given application. Depending on the enduse application and the desired properties, the UV exposure can beperformed on one or more surfaces of the product.

The product where the enhanced properties are needed should be exposedwith a substantially uniform dose of UV light. The exposure can beaccomplished using standard methods known in the art. For example, theUV light can come from any source of UV light such as, but not limitedto, those lamps powered by microwave, HID lamps, and mercury vaporlamps. In some other embodiments, the product is exposed by usingnatural sunlight. The exposure time will be dependent on the applicationand color of material. It can range from a few minutes to several days.Alternatively, the crosslinking can be accomplished by using aUV-emitting light source such as a mercury vapor, High-IntensityDischarge (HID), or various UV lamps. For example, commercial UV lampsare sold for UV curing from manufacturers such as Hereaus Noblelight andFusion UV. Non-limiting examples of UV-emitting light bulbs includemercury bulbs (H bulbs), or metal halide doped mercury bulbs (D bulbs,H+ bulbs, and V bulbs). Other combinations of metal halides to create aUV light source are also contemplated. Exemplary bulbs could also beproduced by assembling the lamp out of UV-absorbing materials andconsidered as a filtered UV source. A mercury arc lamp is not used forirradiation. An H bulb has strong output in the range of 200 nm to 320nm. The D bulb has strong output in the 320 nm to 400 nm range. The Vbulb has strong output in the 400 nm to 420 nm range.

It may also be advantageous to use a UV light source where the harmfulwavelengths (those that cause polymer degradation or excessiveyellowing) are removed or not present. Equipment suppliers such asHeraeus Noblelight and Fusion UV provide lamps with various spectraldistributions. The light can also be filtered to remove harmful orunwanted wavelengths of light. This can be done with optical filtersthat are used to selectively transmit or reject a wavelength or range ofwavelengths. These filters are commercially available from a variety ofcompanies such as Edmund Optics or Praezisions Glas & Optik GmbH.Bandpass filters are designed to transmit a portion of the spectrum,while rejecting all other wavelengths. Longpass edge filters aredesigned to transmit wavelengths greater than the cut-on wavelength ofthe filter. Shortpass edge filters are used to transmit wavelengthsshorter than the cut-off wavelength of the filter. Various types ofmaterials, such as borosilicate glass, can be used as a long passfilter. Schott and/or Praezisions Glas & Optik GmbH for example have thefollowing long pass filters: WG225, WG280, WG295, WG305, WG320 whichhave cut-on wavelengths of ˜225, 280, 295, 305, and 320 nm,respectively. These filters can be used to screen out the harmful shortwavelengths while transmitting the appropriate wavelengths for thecrosslinking reaction.

UV wavelengths can be separated into four different categories. UVArefers to wavelengths from 320 nm to 390 nm. UVB refers to wavelengthsfrom 280 nm to 320 nm. UVC refers to wavelengths from 250 nm to 260 nm.UW refers to wavelengths from 395 nm to 445 nm. These wavelengths oflight were measured with an EIT PowerPuck, and the categories aredefined by the manufacturer (EIT Inc., Sterling, Va.).

The exposed product will have a cross-linked outer surface and an innersurface that is either lightly cross-linked or not cross-linked. Theouter surface can be cross-linked to such a degree that the outersurface is substantially insoluble in the common solvents for thestarting resins. The percentage of the insolubles (insoluble component)will be dependent on the part geometry and surface-to-volume ratio.

The following examples are provided to illustrate the polymers,compositions/blends, products, processes, and properties of the presentdisclosure. The examples are merely illustrative and are not intended tolimit the disclosure to the materials, conditions, or process parametersset forth therein.

Examples

All solvents and reagents used were analytical grade.

Molecular weight determinations were performed using gel permeationchromatography (GPC), using a cross-linked styrene-divinylbenzene columnand calibrated to polycarbonate references using a UV-VIS detector setat 264 nm. Samples were prepared at a concentration of about 1 mg/ml,and eluted at a flow rate of about 1.0 ml/min.

The presence of chloroformate was determined by placing approximately 1mL of reactor organic phase onto paper tape that is impregnated with4-(4-nitrobenzyl)pyridine. A yellow-to-orange color change indicated thepresence of chloroformate groups.

The presence of unreacted bisphenol-A (BPA) in reactor samples wasdetermined by the following method. 2 mL of reactor sample organic phasewas diluted in 5 mL dichloromethane. To the solution was added 5 mLdilute ammonium hydroxide and the mixture shaken vigorously for 30seconds. To the mixture was added 10 mL of 1% aqueous potassiumferricyanide and the mixture shaken vigorously for 30 seconds. To themixture was added 5 mL of 1% aqueous 4-aminoantipyrine and the mixtureshaken vigorously for 30 seconds. A yellow color indicated an acceptablelow amount of residual BPA. An orange to red color indicated anunacceptable high amount of residual BPA.

(A) Preparation of Cross-Linkable Polycarbonate-Polysiloxane Copolymer

Sample A10 was used to make a terpolymer containing 5.3 mole %4,4′-dihydroxybenzophenone (4,4′-DHBP), dimethylsiloxane monomer,remainder bisphenol-A (BPA), using p-cumylphenol (PCP) as an end-cappingagent. The dimethylsiloxane monomer had the structure of Formula (II-a)above, where D is between 10 and 75. Generally, the polysiloxane monomerwas pre-reacted in a tube process, then added directly to a batchcontaining the DHBP, BPA, and PCP.

A solution of p-cumylphenol (168 grams, 0.79 moles, 4.3 mole %) wasprepared in 500 mL of dichloromethane. The p-cumylphenol (PCP) solutionwas placed in an addition pot connected to the reactor via a dosingpump.

A solution of eugenol capped D45 siloxane (312 grams, 0.0082 mole, 5.7wt % siloxane) was prepared in 900 mL of dichloromethane. The D45siloxane solution was placed in an addition tank connected to thetubular reactor via a dosing pump. The tubular reactor (½ inchdiameter×15 feet length, spiral upflow) is connected to the batchreactor.

To the formulation tank was added dichloromethane (13 L), DI water (10L), 4,4′-dihydroxybenzophenone (200 grams, 0.93 moles, 5.3 mole %),bisphenol-A (3800 grams, 16.6 moles), triethylamine (52 grams, 0.37moles) and sodium gluconate (10 grams, iron scavenger). The mixture wasstirred for 5 minutes, then transferred to the 70 L batch reactor whichwas equipped with an overhead condenser, circulation loop, pH probe andvarious material addition nozzles. The formulation tank was rinsed withdichloromethane (5 L) which was transferred to the batch reactor. Thereactor agitator was started and the circulation flow was set at 80L/min. Phosgene vapor flow to the reactor was initiated (80 g/min flowrate) by the DCS and an initial amount (220 grams, 2.2 moles) was added.The pH of the reaction was maintained at a target of 10.0 byDCS-controlled addition of 33% aqueous NaOH.

After addition of the initial amount of phosgene, the PCP solution wasadded to the reactor at 500 mL/min flow rate by DCS control whilephosgene flow to the reactor continued. At the same time the feed to thetubular reactor was initiated with D45 siloxane flow (500 g/min)combining with phosgene (28 g/min, 0.28 mole/min) and 18% aqueous NaOH(316 g/min, 1.4 moles/min) in the plug flow reactor directly feedinginto the batch reactor. The tubular reactor was flushed withdichloromethane (2 L). Phosgene addition continued with pH controlthroughout the additions and until the total set point was reached (2200grams, 22.2 moles). After completion of the phosgene addition, a sampleof the reactor was obtained and verified to be free of un-reacted BPAand free of chloroformate. Mw of a reaction sample was determined by GPCusing a UV detector (Mw=22690, PDI=2.4). An additional charge ofphosgene was added (200 grams, 2.0 mole) to the reactor. The reactor waspurged with nitrogen then the batch was transferred to the centrifugefeed tank.

To the batch in the centrifuge feed tank was added dilutiondichloromethane (8 L) then the mixture was purified using a train ofliquid-liquid centrifuges. Centrifuge one separated the brine phase.Centrifuge two removed the triethylamine catalyst by extracting theresin solution with aqueous hydrochloric acid (pH 1). Centrifuges threethrough eight removed residual ions by extracting the resin solutionwith DI water. A sample of the resin solution was tested and verifiedless than 5 ppm each of ionic chloride and residual triethylamine.

The resin solution was transferred to the precipitation feed tank. Theresin was isolated as a white powder by steam precipitation followed bydrying in a cone shaped vessel using heated nitrogen (210 F). Powderyield 3674 grams. Mw=22460 PDI=2.4.

A sample of the dried polymer resin was hot pressed at 515° F. to give afilm of 295 microns thickness. The film was irradiated using UV light(36 J/cm² UVA, no detectable UVC). The thickness after irradiation was285 microns. The film was submerged in dichloromethane to dissolve thenon-crosslinked polymer. The remaining gel was dried. The thickness ofthe dried gel layer was 49 microns. To another similarly prepared andirradiated film was placed several drops of acetone. After the acetoneevaporated from the irradiated film, no difference was observed betweenthe acetone-tested film and a control film.

The properties of Sample A10 are shown in Table 1 below:

TABLE 1 Sample mol % Mol % Mw PDI Lows % ID Process endcap DHBP UV UV UVA10 siloxane tubular 4.3 5.3 22460 2.4 1.29 reaction, endcap programaddition

The present disclosure has been described with reference to exemplaryembodiments. Obviously, modifications and alterations will occur toothers upon reading and understanding the preceding detaileddescription. It is intended that the present disclosure be construed asincluding all such modifications and alterations insofar as they comewithin the scope of the appended claims or the equivalents thereof.

1. A photoactive additive that is a cross-linkable polycarbonateterpolymer formed from a reaction comprising: a dihydroxybenzophenone; afirst linker moiety comprising a plurality of functional groups, whereineach functional group reacts with the hydroxyl groups of thedihydroxybenzophenone; a diol chain extender; an end-capping agent; anda polysiloxane monomer in an amount such that the additive contains from1 wt % to 25 wt % of siloxane, based on the total weight of thepolycarbonate terpolymer.
 2. The additive of claim 1, wherein thedihydroxybenzophenone is 4,4′-dihydroxybenzophenone; the diol chainextender is bisphenol-A; and the first linker moiety is phosgene.
 3. Theadditive of claim 1, containing from about 0.5 mole % to about 50 mole %of the dihydroxybenzophenone.
 4. The additive of claim 1, containingfrom about 1 wt % to about 25 wt % of the dihydroxybenzophenone.
 5. Theadditive of claim 1, wherein the end-capping agent is selected from thegroup consisting of phenol, p-t-butylphenol, p-cumylphenol, octylphenol,p-cyanophenol, and a monohydroxybenzophenone.
 6. The additive of claim1, wherein the polysiloxane monomer has the structure of one of thefollowing Formulas (I)-(III):

wherein each Ar is independently aryl; each R is independently alkyl,alkoxy, alkenyl, alkenyloxy, aryl, aryloxy, arylalkyl, or alkylaryl;each R₆ is independently C₁-C₃₀ alkyl, C₁-C₃₀ aryl, or C₁-C₃₀ alkylaryl;each M is independently cyano, nitro, alkyl, alkoxy, alkenyl,alkenyloxy, aryl, aryloxy, arylalkyl, or alkylaryl; each n isindependently an integer from 0 to 4; each R₂ is independently analiphatic group; and D and E are an average value of 2 to about
 1000. 7.The additive of claim 1, wherein the diol chain extender has thestructure of one of the following Formulas (A)-(G):

wherein R^(a) and R^(b) each represent a halogen atom or a monovalenthydrocarbon group and may be the same or different; p and q are eachindependently integers of 0 to 4; and A represents one of the groups offormula (A-1):

wherein R^(c) and R^(d) each independently represent a hydrogen atom ora monovalent linear or cyclic hydrocarbon group and R^(e) is a divalenthydrocarbon group;

wherein each R^(k) is independently a C₁₋₁₀ hydrocarbon group, and n is0 to 4;

wherein each X is independently hydrogen, halogen, or alkyl; and j is aninteger from 1 to 20;

wherein R¹³ and R¹⁵ are each independently a halogen or a C₁-C₆ alkylgroup, R¹⁴ is a C₁-C₆ alkyl, phenyl, or phenyl substituted with up tofive halogens or C₁-C₆ alkyl groups, and c is 0 to 4;

wherein R₁ represents a halogen atom, an alkyl group having 1 to 6carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl grouphaving 6 to 12 carbon atoms, an aryl-substituted alkenyl group having 7to 13 carbon atoms, or a fluoroalkyl group having 1 to 6 carbon atoms;R₂ represents a halogen atom, an alkyl group having 1 to 12 carbonatoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having6 to 12 carbon atoms, an aryl-substituted alkenyl group having 7 to 13carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms; mrepresents an integer of 0 to 4; and n represents an integer of 0 to 14;

wherein R₁ to R₄ are each independently a hydrogen atom, a hydrocarbongroup with 1 to 9 carbon atoms which may contain an aromatic group, or ahalogen atom; or

wherein R₁ is an isosorbide unit and R₂-R₉ are each independently ahydrogen, a halogen, a C₁-C₆ alkyl, a methoxy, an ethoxy, or an alkylester.
 8. The additive of claim 1, wherein the first linker moiety hasthe structure of one of the following Formulas (30), (32), or (33):

where Y is hydroxyl, halogen, alkoxy, or aryloxy; and where n is 1 to20.
 9. The additive of claim 1, wherein the molar ratio of thedihydroxybenzophenone to the first linker moiety is from 1:2 to 1:200.10. The additive of claim 1, wherein the reaction that forms thephotoactive additive further comprises a secondary linker moiety havingat least three functional groups, each of which can react with afunctional group of the first linker moiety.
 11. The additive of claim10, wherein the secondary linker moiety has the structure of one of thefollowing Formulas (43)-(48):


12. The additive of claim 1, having a weight average molecular weight of15,000 or greater.
 13. The additive of claim 1, wherein thecross-linkable polycarbonate terpolymer has a weight-average molecularweight from 17,000 to 80,000 Daltons, as measured by gel permeationchromatography using a UV-VIS detector and polycarbonate standards. 14.The additive of claim 1, wherein a molded part formed from thecross-linkable polycarbonate terpolymer exhibits 100% ductility at minus20° C. at 3.2 mm thickness in a notched Izod test according to ASTMD256.
 15. A product formed from a composition comprising the photoactiveadditive of claim
 1. 16. The product of claim 15, wherein the product isat least one of an automotive bumper, an automotive exterior component,an automobile mirror housing, an automobile grille, an automobilepillar, an automobile wheel cover, an automobile instrument panel ortrim, an automobile glove box, an automobile door hardware or otherinterior trim, an automobile exterior light, an automobile part withinthe engine compartment, an agricultural tractor or device part, aconstruction equipment vehicle or device part, a construction oragricultural equipment grille, a marine or personal water craft part, anall terrain vehicle or all terrain vehicle part, plumbing equipment, avalve or pump, an air conditioning heating or cooling part, a furnace orheat pump part, a computer part, a computer router, a desk top printer,a large office/industrial printer, an electronics part, a projectorpart, an electronic display part, a copier part, a scanner part, anelectronic printer toner cartridge, a hair drier, an iron, a coffeemaker, a toaster, a washing machine or washing machine part, amicrowave, an oven, a power tool, an electric component, an electricenclosure, a lighting part, a dental instrument, a medical instrument, amedical or dental lighting part, an aircraft part, a train or rail part,a seating component, a sidewall, a ceiling part, cookware, a medicalinstrument tray, an animal cage, fibers, a laser welded medical device,fiber optics, a lense (auto and non-auto), a cell phone part, agreenhouse component, a sun room component, a fire helmet, a safetyshield, safety glasses, a gas pump part, a humidifier housing, athermostat control housing, an air conditioner drain pan, an outdoorcabinet, a telecom enclosure or infrastructure, a Simple NetworkDetection System (SNIDS) device, a network interface device, a smokedetector, a component or device in a plenum space, a medical scanner,X-ray equipment, a construction or agricultural equipment, a hand heldelectronic device enclosure or part, a wearable electronic device, ahand held tool enclosure or part, a smart phone enclosure or part, and aturbine blade.
 17. The product of claim 15, wherein the product is amolded article, a film, a sheet, a layer of a multilayer film, or alayer of a multilayer sheet.
 18. The product of claim 15, wherein theproduct is formed by injection molding, overmolding, co-injectionmolding, extrusion, multilayer extrusion, rotational molding, blowmolding, or thermoforming.
 19. The product of claim 15, wherein theproduct is exposed to UV radiation to cause crosslinking of thephotoactive additive.
 20. A blend comprising the additive of claim 1 anda polymeric base resin that is different from the photoactive additive.21. A process for making a photoactive additive from adihydroxybenzophenone, a diol chain extender, a polysiloxane monomer, anend-capping agent, a carbonate precursor, a base, a tertiary aminecatalyst, water, and a water-immiscible organic solvent, comprising:pre-reacting the polysiloxane monomer with the carbonate precursor in atubular reactor to form chloroformates; combining thedihydroxybenzophenone, diol chain extender, tertiary amine catalyst,water, and water-immiscible solvent to form a reaction mixture; addingthe carbonate precursor to the reaction mixture over a first time periodwhile co-adding the base to regulate the reaction pH; adding theend-capping agent and the chloroformates to the reaction mixture for asecond time period while continuing to add the carbonate precursor andthe base; and continuing to add the carbonate precursor and the base tothe reaction mixture for a third time period after the second timeperiod is complete to obtain the photoactive additive; wherein thepolysiloxane monomer is present in an amount such that the additivecontains from 1 wt % to 25 wt % of siloxane, based on the total weightof the polycarbonate resin.
 22. The process of claim 21, wherein thecarbonate precursor is phosgene, the diol chain extender is bisphenol-A,the base is an alkali metal hydroxide, and the water-immiscible organicsolvent is methylene chloride.
 23. The process of claim 21, wherein theend-capping agent is dissolved in a solvent prior to being added to thereaction mixture, the solvent being either the water-immiscible organicsolvent or water containing a base.
 24. The process of claim 23, whereinthe end-capping agent is dissolved in a dilute aqueous sodium hydroxidesolution.
 25. The process of claim 24, wherein the solution containsfrom about 1 to about 2 moles of NaOH per mole of the end-capping agent,and contains from about 5 wt % to about 20 wt % of the end-capping agentcompound.
 26. The process of claim 21, wherein the reaction pH isregulated to remain between about 8.5 and about
 10. 27. A cross-linkablepolycarbonate terpolymer formed from a reaction comprising adihydroxybenzophenone, a diol chain extender, and a polysiloxane monomerin an amount such that the terpolymer contains from 1 wt % to 25 wt % ofsiloxane, based on the total weight of the terpolymer, wherein theterpolymer is formed by: pre-reacting the polysiloxane monomer with acarbonate precursor in a tubular reactor to form chloroformates;combining the dihydroxybenzophenone, the diol chain extender, a tertiaryamine catalyst, water, and a water-immiscible solvent to form a reactionmixture; adding the carbonate precursor to the reaction mixture over afirst time period while co-adding the base to regulate the reaction pH;adding the chloroformates to the reaction mixture for a second timeperiod while continuing to add the carbonate precursor and the base; andcontinuing to add the carbonate precursor and the base to the reactionmixture for a third time period after the second time period is completeto obtain the terpolymer.
 28. A crosslinked layer formed from apolymeric blend that has been exposed to UV radiation, the blendcomprising: a photoactive additive that is a cross-linkablepolycarbonate terpolymer formed from a reaction comprising adihydroxybenzophenone, a diol chain extender, and a polysiloxane monomerin an amount such that the terpolymer contains from 1 wt % to 25 wt % ofsiloxane, based on the total weight of the terpolymer; and a polymerresin which is different from the photoactive additive.
 29. The layer ofclaim 28, wherein the crosslinked layer contains chains from both thephotoactive additive and the polymer resin.
 30. The layer of claim 28,wherein the crosslinking is sufficient to create a continuous insolublelayer containing both the photoactive additive and the polymer resin.